CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR THE SIXTH CIRCUIT

[225] Joel W. Sternman argued the cause for petitioners. With him on the briefs were H. Stephen Madsen, Norman S. Jeavons, William W. Golub, Ambrose Doskow, Arnold I. Roth, and Katherine M. Blakeley.

[226] Wayne A. Cross argued the cause for respondents. With him on the brief were David S. Elkind and Lee A. Pickard.^[*]

Solicitor General Fried, Deputy Solicitor General Cohen, Jerrold J. Ganzfried, Daniel L. Goelzer, Paul Gonson, Jacob H. Stillman, Eric Summergrad, Katharine B. Gresham, and Max Berueffy filed a brief for the United States as amicus curiae.

JUSTICE BLACKMUN delivered the opinion of the Court.

This case requires us to apply the materiality requirement of § 10(b) of the Securities Exchange Act of 1934 (1934 Act), 48 Stat. 881, as amended, 15 U. S. C. § 78a et seq., and the Securities and Exchange Commission's Rule 10b-5, 17 CFR § 240.10b-5 (1987), promulgated thereunder, in the context of preliminary corporate merger discussions. We must also determine whether a person who traded a corporation's shares on a securities exchange after the issuance of a materially misleading statement by the corporation may invoke a rebuttable presumption that, in trading, he relied on the integrity of the price set by the market.

I

Prior to December 20, 1978, Basic Incorporated was a publicly traded company primarily engaged in the business of manufacturing chemical refractories for the steel industry. As early as 1965 or 1966, Combustion Engineering, Inc., a company producing mostly alumina-based refractories, expressed some interest in acquiring Basic, but was deterred from pursuing this inclination seriously because of antitrust concerns it then entertained. See App. 81-83. In 1976, however, regulatory action opened the way to a renewal of [227] Combustion's interest.^[1] The "Strategic Plan," dated October 25, 1976, for Combustion's Industrial Products Group included the objective: "Acquire Basic Inc. $30 million." App. 337.

Beginning in September 1976, Combustion representatives had meetings and telephone conversations with Basic officers and directors, including petitioners here,^[2] concerning the possibility of a merger.^[3] During 1977 and 1978, Basic made three public statements denying that it was engaged in merger negotiations.^[4] On December 18, 1978, Basic asked [228] the New York Stock Exchange to suspend trading in its shares and issued a release stating that it had been "approached" by another company concerning a merger. Id., at 413. On December 19, Basic's board endorsed Combustion's offer of $46 per share for its common stock, id., at 335, 414-416, and on the following day publicly announced its approval of Combustion's tender offer for all outstanding shares.

Respondents are former Basic shareholders who sold their stock after Basic's first public statement of October 21, 1977, and before the suspension of trading in December 1978. Respondents brought a class action against Basic and its directors, asserting that the defendants issued three false or misleading public statements and thereby were in violation of § 10(b) of the 1934 Act and of Rule 10b-5. Respondents alleged that they were injured by selling Basic shares at artificially depressed prices in a market affected by petitioners' misleading statements and in reliance thereon.

The District Court adopted a presumption of reliance by members of the plaintiff class upon petitioners' public statements that enabled the court to conclude that common questions of fact or law predominated over particular questions pertaining to individual plaintiffs. See Fed. Rule Civ. Proc. 23(b)(3). The District Court therefore certified respondents' class.^[5] On the merits, however, the District Court granted [229] summary judgment for the defendants. It held that, as a matter of law, any misstatements were immaterial: there were no negotiations ongoing at the time of the first statement, and although negotiations were taking place when the second and third statements were issued, those negotiations were not "destined, with reasonable certainty, to become a merger agreement in principle." App. to Pet. for Cert. 103a.

The United States Court of Appeals for the Sixth Circuit affirmed the class certification, but reversed the District Court's summary judgment, and remanded the case. 786 F. 2d 741 (1986). The court reasoned that while petitioners were under no general duty to disclose their discussions with Combustion, any statement the company voluntarily released could not be " `so incomplete as to mislead.' " Id., at 746, quoting SEC v. Texas Gulf Sulphur Co., 401 F. 2d 833, 862 (CA2 1968) (en banc), cert. denied sub nom. Coates v. SEC, 394 U. S. 976 (1969). In the Court of Appeals' view, Basic's statements that no negotiations were taking place, and that it knew of no corporate developments to account for the heavy trading activity, were misleading. With respect to materiality, the court rejected the argument that preliminary merger discussions are immaterial as a matter of law, and held that "once a statement is made denying the existence of any discussions, even discussions that might not have been material in absence of the denial are material because they make the statement made untrue." 786 F. 2d, at 749.

The Court of Appeals joined a number of other Circuits in accepting the "fraud-on-the-market theory" to create a rebuttable presumption that respondents relied on petitioners' material [230] misrepresentations, noting that without the presumption it would be impractical to certify a class under Federal Rule of Civil Procedure 23(b)(3). See 786 F. 2d, at 750-751.

We granted certiorari, 479 U. S. 1083 (1987), to resolve the split, see Part III, infra, among the Courts of Appeals as to the standard of materiality applicable to preliminary merger discussions, and to determine whether the courts below properly applied a presumption of reliance in certifying the class, rather than requiring each class member to show direct reliance on Basic's statements.

II

The 1934 Act was designed to protect investors against manipulation of stock prices. See S. Rep. No. 792, 73d Cong., 2d Sess., 1-5 (1934). Underlying the adoption of extensive disclosure requirements was a legislative philosophy: "There cannot be honest markets without honest publicity. Manipulation and dishonest practices of the market place thrive upon mystery and secrecy." H. R. Rep. No. 1383, 73d Cong., 2d Sess., 11 (1934). This Court "repeatedly has described the `fundamental purpose' of the Act as implementing a `philosophy of full disclosure.' " Santa Fe Industries, Inc. v. Green, 430 U. S. 462, 477-478 (1977), quoting SEC v. Capital Gains Research Bureau, Inc., 375 U. S. 180, 186 (1963).

Pursuant to its authority under § 10(b) of the 1934 Act, 15 U. S. C. § 78j, the Securities and Exchange Commission promulgated Rule 10b-5.^[6] Judicial interpretation and application, [231] legislative acquiescence, and the passage of time have removed any doubt that a private cause of action exists for a violation of § 10(b) and Rule 10b-5, and constitutes an essential tool for enforcement of the 1934 Act's requirements. See, e. g., Ernst & Ernst v. Hochfelder, 425 U. S. 185, 196 (1976); Blue Chip Stamps v. Manor Drug Stores, 421 U. S. 723, 730 (1975).

The Court previously has addressed various positive and common-law requirements for a violation of § 10(b) or of Rule 10b-5. See, e. g., Santa Fe Industries, Inc. v. Green, supra ("manipulative or deceptive" requirement of the statute); Blue Chip Stamps v. Manor Drug Stores, supra ("in connection with the purchase or sale" requirement of the Rule); Dirks v. SEC, 463 U. S. 646 (1983) (duty to disclose); Chiarella v. United States, 445 U. S. 222 (1980) (same); Ernst & Ernst v. Hochfelder, supra (scienter). See also Carpenter v. United States, 484 U. S. 19 (1987) (confidentiality). The Court also explicitly has defined a standard of materiality under the securities laws, see TSC Industries, Inc. v. Northway, Inc., 426 U. S. 438 (1976), concluding in the proxy-solicitation context that "[a]n omitted fact is material if there is a substantial likelihood that a reasonable shareholder would consider it important in deciding how to vote." Id., at 449.^[7] Acknowledging that certain information concerning corporate developments could well be of "dubious significance," id., at 448, the Court was careful not to set too low a standard of materiality; it was concerned that a minimal standard might bring an overabundance of information within its reach, and lead management "simply to bury the shareholders in an avalanche of trivial information — a result that is hardly conducive to informed decisionmaking." Id., at 448-449. It further explained that to fulfill the materiality requirement "there must be a substantial likelihood that the disclosure of the omitted fact would have been viewed by the [232] reasonable investor as having significantly altered the `total mix' of information made available." Id., at 449. We now expressly adopt the TSC Industries standard of materiality for the § 10(b) and Rule 10b-5 context.^[8]

III

The application of this materiality standard to preliminary merger discussions is not self-evident. Where the impact of the corporate development on the target's fortune is certain and clear, the TSC Industries materiality definition admits straightforward application. Where, on the other hand, the event is contingent or speculative in nature, it is difficult to ascertain whether the "reasonable investor" would have considered the omitted information significant at the time. Merger negotiations, because of the ever-present possibility that the contemplated transaction will not be effectuated, fall into the latter category.^[9]

A

Petitioners urge upon us a Third Circuit test for resolving this difficulty.^[10] See Brief for Petitioners 20-22. Under this [233] approach, preliminary merger discussions do not become material until "agreement-in-principle" as to the price and structure of the transaction has been reached between the would-be merger partners. See Greenfield v. Heublein, Inc., 742 F. 2d 751, 757 (CA3 1984), cert. denied, 469 U. S. 1215 (1985). By definition, then, information concerning any negotiations not yet at the agreement-in-principle stage could be withheld or even misrepresented without a violation of Rule 10b-5.

Three rationales have been offered in support of the "agreement-in-principle" test. The first derives from the concern expressed in TSC Industries that an investor not be overwhelmed by excessively detailed and trivial information, and focuses on the substantial risk that preliminary merger discussions may collapse: because such discussions are inherently tentative, disclosure of their existence itself could mislead investors and foster false optimism. See Greenfield v. Heublein, Inc., 742 F. 2d, at 756; Reiss v. Pan American World Airways, Inc., 711 F. 2d 11, 14 (CA2 1983). The other two justifications for the agreement-in-principle standard are based on management concerns: because the requirement of "agreement-in-principle" limits the scope of disclosure obligations, it helps preserve the confidentiality of merger discussions where earlier disclosure might prejudice the negotiations; and the test also provides a usable, bright-line rule for determining when disclosure must be made. See Greenfield v. Heublein, Inc., 742 F. 2d, at 757; Flamm [234] v. Eberstadt, 814 F. 2d 1169, 1176-1178 (CA7), cert. denied, 484 U. S. 853 (1987).

None of these policy-based rationales, however, purports to explain why drawing the line at agreement-in-principle reflects the significance of the information upon the investor's decision. The first rationale, and the only one connected to the concerns expressed in TSC Industries, stands soundly rejected, even by a Court of Appeals that otherwise has accepted the wisdom of the agreement-in-principle test. "It assumes that investors are nitwits, unable to appreciate — even when told — that mergers are risky propositions up until the closing." Flamm v. Eberstadt, 814 F. 2d, at 1175. Disclosure, and not paternalistic withholding of accurate information, is the policy chosen and expressed by Congress. We have recognized time and again, a "fundamental purpose" of the various Securities Acts, "was to substitute a philosophy of full disclosure for the philosophy of caveat emptor and thus to achieve a high standard of business ethics in the securities industry." SEC v. Capital Gains Research Bureau, Inc., 375 U. S., at 186. Accord, Affiliated Ute Citizens v. United States, 406 U. S. 128, 151 (1972); Santa Fe Industries, Inc. v. Green, 430 U. S., at 477. The role of the materiality requirement is not to "attribute to investors a child-like simplicity, and inability to grasp the probabilistic significance of negotiations," Flamm v. Eberstadt, 814 F. 2d, at 1175, but to filter out essentially useless information that a reasonable investor would not consider significant, even as part of a larger "mix" of factors to consider in making his investment decision. TSC Industries, Inc. v. Northway, Inc., 426 U. S., at 448-449.

The second rationale, the importance of secrecy during the early stages of merger discussions, also seems irrelevant to an assessment whether their existence is significant to the trading decision of a reasonable investor. To avoid a "bidding war" over its target, an acquiring firm often will insist that negotiations remain confidential, see, e. g., In re Carnation [235] Co., Exchange Act Release No. 22214, 33 S. E. C. Docket 1025 (1985), and at least one Court of Appeals has stated that "silence pending settlement of the price and structure of a deal is beneficial to most investors, most of the time." Flamm v. Eberstadt, 814 F. 2d, at 1177.^[11]

We need not ascertain, however, whether secrecy necessarily maximizes shareholder wealth — although we note that the proposition is at least disputed as a matter of theory and empirical research^[12] — for this case does not concern the timing of a disclosure; it concerns only its accuracy and completeness.^[13] We face here the narrow question whether information concerning the existence and status of preliminary merger discussions is significant to the reasonable investor's trading decision. Arguments based on the premise that some disclosure would be "premature" in a sense are more properly considered under the rubric of an issuer's duty to disclose. The "secrecy" rationale is simply inapposite to the definition of materiality.

[236] The final justification offered in support of the agreement-in-principle test seems to be directed solely at the comfort of corporate managers. A bright-line rule indeed is easier to follow than a standard that requires the exercise of judgment in the light of all the circumstances. But ease of application alone is not an excuse for ignoring the purposes of the Securities Acts and Congress' policy decisions. Any approach that designates a single fact or occurrence as always determinative of an inherently fact-specific finding such as materiality, must necessarily be overinclusive or underinclusive. In TSC Industries this Court explained: "The determination [of materiality] requires delicate assessments of the inferences a `reasonable shareholder' would draw from a given set of facts and the significance of those inferences to him . . . ." 426 U. S., at 450. After much study, the Advisory Committee on Corporate Disclosure cautioned the SEC against administratively confining materiality to a rigid formula.^[14] Courts also would do well to heed this advice.

We therefore find no valid justification for artificially excluding from the definition of materiality information concerning merger discussions, which would otherwise be considered significant to the trading decision of a reasonable investor, merely because agreement-in-principle as to price and structure has not yet been reached by the parties or their representatives.

B

[237] The Sixth Circuit explicitly rejected the agreement-in-principle test, as we do today, but in its place adopted a rule that, if taken literally, would be equally insensitive, in our view, to the distinction between materiality and the other elements of an action under Rule 10b-5:

"When a company whose stock is publicly traded makes a statement, as Basic did, that `no negotiations' are underway, and that the corporation knows of `no reason for the stock's activity,' and that `management is unaware of any present or pending corporate development that would result in the abnormally heavy trading activity,' information concerning ongoing acquisition discussions becomes material by virtue of the statement denying their existence. . . .

.....

". . . In analyzing whether information regarding merger discussions is material such that it must be affirmatively disclosed to avoid a violation of Rule 10b-5, the discussions and their progress are the primary considerations. However, once a statement is made denying the existence of any discussions, even discussions that might not have been material in absence of the denial are material because they make the statement made untrue." 786 F. 2d, at 748-749 (emphasis in original).^[15]

[238] This approach, however, fails to recognize that, in order to prevail on a Rule 10b-5 claim, a plaintiff must show that the statements were misleading as to a material fact. It is not enough that a statement is false or incomplete, if the misrepresented fact is otherwise insignificant.

C

Even before this Court's decision in TSC Industries, the Second Circuit had explained the role of the materiality requirement of Rule 10b-5, with respect to contingent or speculative information or events, in a manner that gave that term meaning that is independent of the other provisions of the Rule. Under such circumstances, materiality "will depend at any given time upon a balancing of both the indicated probability that the event will occur and the anticipated magnitude of the event in light of the totality of the company activity." SEC v. Texas Gulf Sulphur Co., 401 F. 2d, at 849. Interestingly, neither the Third Circuit decision adopting the agreement-in-principle test nor petitioners here take issue with this general standard. Rather, they suggest that with respect to preliminary merger discussions, there are good reasons to draw a line at agreement on price and structure.

In a subsequent decision, the late Judge Friendly, writing for a Second Circuit panel, applied the Texas Gulf Sulphur probability/magnitude approach in the specific context of preliminary merger negotiations. After acknowledging that materiality is something to be determined on the basis of the particular facts of each case, he stated:

"Since a merger in which it is bought out is the most important event that can occur in a small corporation's life, to wit, its death, we think that inside information, as regards a merger of this sort, can become material at an earlier stage than would be the case as regards lesser transactions — and this even though the mortality rate of mergers in such formative stages is doubtless high." SEC v. Geon Industries, Inc., 531 F. 2d 39, 47-48 (1976).

[239] We agree with that analysis.^[16]

Whether merger discussions in any particular case are material therefore depends on the facts. Generally, in order to assess the probability that the event will occur, a factfinder will need to look to indicia of interest in the transaction at the highest corporate levels. Without attempting to catalog all such possible factors, we note by way of example that board resolutions, instructions to investment bankers, and actual negotiations between principals or their intermediaries may serve as indicia of interest. To assess the magnitude of the transaction to the issuer of the securities allegedly manipulated, a factfinder will need to consider such facts as the size of the two corporate entities and of the potential premiums over market value. No particular event or factor short of closing the transaction need be either necessary or sufficient by itself to render merger discussions material.^[17]

[240] As we clarify today, materiality depends on the significance the reasonable investor would place on the withheld or misrepresented information.^[18] The fact-specific inquiry we endorse here is consistent with the approach a number of courts have taken in assessing the materiality of merger negotiations.^[19] Because the standard of materiality we have [241] adopted differs from that used by both courts below, we remand the case for reconsideration of the question whether a grant of summary judgment is appropriate on this record.^[20]

IV

A

We turn to the question of reliance and the fraud-on-the-market theory. Succinctly put:

"The fraud on the market theory is based on the hypothesis that, in an open and developed securities market, the price of a company's stock is determined by the available material information regarding the company and its business. . . . Misleading statements will therefore [242] defraud purchasers of stock even if the purchasers do not directly rely on the misstatements. . . . The causal connection between the defendants' fraud and the plaintiffs' purchase of stock in such a case is no less significant than in a case of direct reliance on misrepresentations." Peil v. Speiser, 806 F. 2d 1154, 1160-1161 (CA3 1986).

Our task, of course, is not to assess the general validity of the theory, but to consider whether it was proper for the courts below to apply a rebuttable presumption of reliance, supported in part by the fraud-on-the-market theory. Cf. the comments of the dissent, post, at 252-255.

This case required resolution of several common questions of law and fact concerning the falsity or misleading nature of the three public statements made by Basic, the presence or absence of scienter, and the materiality of the misrepresentations, if any. In their amended complaint, the named plaintiffs alleged that in reliance on Basic's statements they sold their shares of Basic stock in the depressed market created by petitioners. See Amended Complaint in No. C79-1220 (ND Ohio), ¶¶ 27, 29, 35, 40; see also id., ¶ 33 (alleging effect on market price of Basic's statements). Requiring proof of individualized reliance from each member of the proposed plaintiff class effectively would have prevented respondents from proceeding with a class action, since individual issues then would have overwhelmed the common ones. The District Court found that the presumption of reliance created by the fraud-on-the-market theory provided "a practical resolution to the problem of balancing the substantive requirement of proof of reliance in securities cases against the procedural requisites of [Federal Rule of Civil Procedure] 23." The District Court thus concluded that with reference to each public statement and its impact upon the open market for Basic shares, common questions predominated over individual questions, as required by Federal Rules of Civil Procedure 23(a)(2) and (b)(3).

[243] Petitioners and their amici complain that the fraud-on-the-market theory effectively eliminates the requirement that a plaintiff asserting a claim under Rule 10b-5 prove reliance. They note that reliance is and long has been an element of common-law fraud, see, e. g., Restatement (Second) of Torts § 525 (1977); W. Keeton, D. Dobbs, R. Keeton, & D. Owen, Prosser and Keeton on Law of Torts § 108 (5th ed. 1984), and argue that because the analogous express right of action includes a reliance requirement, see, e. g., § 18(a) of the 1934 Act, as amended, 15 U. S. C. § 78r(a), so too must an action implied under § 10(b).

We agree that reliance is an element of a Rule 10b-5 cause of action. See Ernst & Ernst v. Hochfelder, 425 U. S., at 206 (quoting Senate Report). Reliance provides the requisite causal connection between a defendant's misrepresentation and a plaintiff's injury. See, e. g., Wilson v. Comtech Telecommunications Corp., 648 F. 2d 88, 92 (CA2 1981); List v. Fashion Park, Inc., 340 F. 2d 457, 462 (CA2), cert. denied sub nom. List v. Lerner, 382 U. S. 811 (1965). There is, however, more than one way to demonstrate the causal connection. Indeed, we previously have dispensed with a requirement of positive proof of reliance, where a duty to disclose material information had been breached, concluding that the necessary nexus between the plaintiffs' injury and the defendant's wrongful conduct had been established. See Affiliated Ute Citizens v. United States, 406 U. S., at 153-154. Similarly, we did not require proof that material omissions or misstatements in a proxy statement decisively affected voting, because the proxy solicitation itself, rather than the defect in the solicitation materials, served as an essential link in the transaction. See Mills v. Electric Auto-Lite Co., 396 U. S. 375, 384-385 (1970).

The modern securities markets, literally involving millions of shares changing hands daily, differ from the face-to-face [244] transactions contemplated by early fraud cases,^[21] and our understanding of Rule 10b-5's reliance requirement must encompass these differences.^[22]

"In face-to-face transactions, the inquiry into an investor's reliance upon information is into the subjective pricing of that information by that investor. With the presence of a market, the market is interposed between seller and buyer and, ideally, transmits information to the investor in the processed form of a market price. Thus the market is performing a substantial part of the valuation process performed by the investor in a face-to-face transaction. The market is acting as the unpaid agent of the investor, informing him that given all the information available to it, the value of the stock is worth the market price." In re LTV Securities Litigation, 88 F. R. D. 134, 143 (ND Tex. 1980).

Accord, e. g., Peil v. Speiser, 806 F. 2d, at 1161 ("In an open and developed market, the dissemination of material misrepresentations or withholding of material information typically affects the price of the stock, and purchasers generally rely on the price of the stock as a reflection of its value"); Blackie [245] v. Barrack, 524 F. 2d 891, 908 (CA9 1975) ("[T]he same causal nexus can be adequately established indirectly, by proof of materiality coupled with the common sense that a stock purchaser does not ordinarily seek to purchase a loss in the form of artificially inflated stock"), cert. denied, 429 U. S. 816 (1976).

B

Presumptions typically serve to assist courts in managing circumstances in which direct proof, for one reason or another, is rendered difficult. See, e. g., 1 D. Louisell & C. Mueller, Federal Evidence 541-542 (1977). The courts below accepted a presumption, created by the fraud-on-the-market theory and subject to rebuttal by petitioners, that persons who had traded Basic shares had done so in reliance on the integrity of the price set by the market, but because of petitioners' material misrepresentations that price had been fraudulently depressed. Requiring a plaintiff to show a speculative state of facts, i. e., how he would have acted if omitted material information had been disclosed, see Affiliated Ute Citizens v. United States, 406 U. S., at 153-154, or if the misrepresentation had not been made, see Sharp v. Coopers & Lybrand, 649 F. 2d 175, 188 (CA3 1981), cert. denied, 455 U. S. 938 (1982), would place an unnecessarily unrealistic evidentiary burden on the Rule 10b-5 plaintiff who has traded on an impersonal market. Cf. Mills v. Electric Auto-Lite Co., 396 U. S., at 385.

Arising out of considerations of fairness, public policy, and probability, as well as judicial economy, presumptions are also useful devices for allocating the burdens of proof between parties. See E. Cleary, McCormick on Evidence 968-969 (3d ed. 1984); see also Fed. Rule Evid. 301 and Advisory Committee Notes, 28 U. S. C. App., p. 685. The presumption of reliance employed in this case is consistent with, and, by facilitating Rule 10b-5 litigation, supports, the congressional policy embodied in the 1934 Act. In drafting that Act, [246] Congress expressly relied on the premise that securities markets are affected by information, and enacted legislation to facilitate an investor's reliance on the integrity of those markets:

"No investor, no speculator, can safely buy and sell securities upon the exchanges without having an intelligent basis for forming his judgment as to the value of the securities he buys or sells. The idea of a free and open public market is built upon the theory that competing judgments of buyers and sellers as to the fair price of a security brings [sic] about a situation where the market price reflects as nearly as possible a just price. Just as artificial manipulation tends to upset the true function of an open market, so the hiding and secreting of important information obstructs the operation of the markets as indices of real value." H. R. Rep. No. 1383, at 11.

See Lipton v. Documation, Inc., 734 F. 2d 740, 748 (CA11 1984), cert. denied, 469 U. S. 1132 (1985).^[23]

The presumption is also supported by common sense and probability. Recent empirical studies have tended to confirm Congress' premise that the market price of shares traded on well-developed markets reflects all publicly available information, and, hence, any material misrepresentations.^[24] It has been noted that "it is hard to imagine that [247] there ever is a buyer or seller who does not rely on market integrity. Who would knowingly roll the dice in a crooked crap game?" Schlanger v. Four-Phase Systems Inc., 555 F. Supp. 535, 538 (SDNY 1982). Indeed, nearly every court that has considered the proposition has concluded that where materially misleading statements have been disseminated into an impersonal, well-developed market for securities, the reliance of individual plaintiffs on the integrity of the market price may be presumed.^[25] Commentators generally have applauded the adoption of one variation or another of the fraud-on-the-market theory.^[26] An investor who buys or sells stock at the price set by the market does so in reliance on the integrity of that price. Because most publicly available information is reflected in market price, an investor's reliance on any public material misrepresentations, therefore, may be presumed for purposes of a Rule 10b-5 action.

C

[248] The Court of Appeals found that petitioners "made public, material misrepresentations and [respondents] sold Basic stock in an impersonal, efficient market. Thus the class, as defined by the district court, has established the threshold facts for proving their loss." 786 F. 2d, at 751.^[27] The court acknowledged that petitioners may rebut proof of the elements giving rise to the presumption, or show that the misrepresentation in fact did not lead to a distortion of price or that an individual plaintiff traded or would have traded despite his knowing the statement was false. Id., at 750, n. 6.

Any showing that severs the link between the alleged misrepresentation and either the price received (or paid) by the plaintiff, or his decision to trade at a fair market price, will be sufficient to rebut the presumption of reliance. For example, if petitioners could show that the "market makers" were privy to the truth about the merger discussions here with Combustion, and thus that the market price would not have been affected by their misrepresentation, the causal connection could be broken: the basis for finding that the fraud had been transmitted through market price would be gone.^[28] Similarly, if, despite petitioners' allegedly fraudulent attempt [249] to manipulate market price, news of the merger discussions credibly entered the market and dissipated the effects of the misstatements, those who traded Basic shares after the corrective statements would have no direct or indirect connection with the fraud.^[29] Petitioners also could rebut the presumption of reliance as to plaintiffs who would have divested themselves of their Basic shares without relying on the integrity of the market. For example, a plaintiff who believed that Basic's statements were false and that Basic was indeed engaged in merger discussions, and who consequently believed that Basic stock was artificially underpriced, but sold his shares nevertheless because of other unrelated concerns, e. g., potential antitrust problems, or political pressures to divest from shares of certain businesses, could not be said to have relied on the integrity of a price he knew had been manipulated.

V

In summary:

1. We specifically adopt, for the § 10(b) and Rule 10b-5 context, the standard of materiality set forth in TSC Industries, Inc. v. Northway, Inc., 426 U. S., at 449.

2. We reject "agreement-in-principle as to price and structure" as the bright-line rule for materiality.

3. We also reject the proposition that "information becomes material by virtue of a public statement denying it."

[250] 4. Materiality in the merger context depends on the probability that the transaction will be consummated, and its significance to the issuer of the securities. Materiality depends on the facts and thus is to be determined on a case-by-case basis.

5. It is not inappropriate to apply a presumption of reliance supported by the fraud-on-the-market theory.

6. That presumption, however, is rebuttable.

7. The District Court's certification of the class here was appropriate when made but is subject on remand to such adjustment, if any, as developing circumstances demand.

The judgment of the Court of Appeals is vacated, and the case is remanded to that court for further proceedings consistent with this opinion.

It is so ordered.

THE CHIEF JUSTICE, JUSTICE SCALIA, and JUSTICE KENNEDY took no part in the consideration or decision of this case.

JUSTICE WHITE, with whom JUSTICE O'CONNOR joins, concurring in part and dissenting in part.

I join Parts I-III of the Court's opinion, as I agree that the standard of materiality we set forth in TSC Industries, Inc. v. Northway, Inc., 426 U. S. 438, 449 (1976), should be applied to actions under § 10(b) and Rule 10b-5. But I dissent from the remainder of the Court's holding because I do not agree that the "fraud-on-the-market" theory should be applied in this case.

I

Even when compared to the relatively youthful private cause-of-action under § 10(b), see Kardon v. National Gypsum Co., 69 F. Supp. 512 (ED Pa. 1946), the fraud-on-the-market theory is a mere babe.^[1] Yet today, the Court embraces [251] this theory with the sweeping confidence usually reserved for more mature legal doctrines. In so doing, I fear that the Court's decision may have many adverse, unintended effects as it is applied and interpreted in the years to come.

A

At the outset, I note that there are portions of the Court's fraud-on-the-market holding with which I am in agreement. Most importantly, the Court rejects the version of that theory, heretofore adopted by some courts,^[2] which equates "causation" with "reliance," and permits recovery by a plaintiff who claims merely to have been harmed by a material misrepresentation which altered a market price, notwithstanding proof that the plaintiff did not in any way rely on that price. Ante, at 248. I agree with the Court that if Rule 10b-5's reliance requirement is to be left with any content at all, the fraud-on-the-market presumption must be capable of being rebutted by a showing that a plaintiff did not "rely" on the market price. For example, a plaintiff who decides, months in advance of an alleged misrepresentation, to purchase a stock; one who buys or sells a stock for reasons unrelated to its price; one who actually sells a stock "short" days before the misrepresentation is made — surely none of these people can state a valid claim under Rule 10b-5. Yet, some federal courts have allowed such claims to stand under one variety or another of the fraud-on-the-market theory.^[3]

[252] Happily, the majority puts to rest the prospect of recovery under such circumstances. A nonrebuttable presumption of reliance — or even worse, allowing recovery in the face of "affirmative evidence of nonreliance," Zweig v. Hearst Corp., 594 F. 2d 1261, 1272 (CA9 1979) (Ely, J., dissenting) — would effectively convert Rule 10b-5 into "a scheme of investor's insurance." Shores v. Sklar, 647 F. 2d 462, 469, n. 5 (CA5 1981) (en banc), cert. denied, 459 U. S. 1102 (1983). There is no support in the Securities Exchange Act, the Rule, or our cases for such a result.

B

But even as the Court attempts to limit the fraud-on-the-market theory it endorses today, the pitfalls in its approach are revealed by previous uses by the lower courts of the broader versions of the theory. Confusion and contradiction in court rulings are inevitable when traditional legal analysis is replaced with economic theorization by the federal courts.

[253] In general, the case law developed in this Court with respect to § 10(b) and Rule 10b-5 has been based on doctrines with which we, as judges, are familiar: common-law doctrines of fraud and deceit. See, e. g., Santa Fe Industries, Inc. v. Green, 430 U. S. 462, 471-477 (1977). Even when we have extended civil liability under Rule 10b-5 to a broader reach than the common law had previously permitted, see ante, at 244, n. 22, we have retained familiar legal principles as our guideposts. See, e. g., Herman & MacLean v. Huddleston, 459 U. S. 375, 389-390 (1983). The federal courts have proved adept at developing an evolving jurisprudence of Rule 10b-5 in such a manner. But with no staff economists, no experts schooled in the "efficient-capital-market hypothesis," no ability to test the validity of empirical market studies, we are not well equipped to embrace novel constructions of a statute based on contemporary microeconomic theory.^[4]

The "wrong turns" in those Court of Appeals and District Court fraud-on-the-market decisions which the Court implicitly rejects as going too far should be ample illustration of the dangers when economic theories replace legal rules as the basis for recovery. Yet the Court today ventures into this area beyond its expertise, beyond — by its own admission — the confines of our previous fraud cases. See ante, at 243-244. Even if I agreed with the Court that "modern securities [254] markets . . . involving millions of shares changing hands daily" require that the "understanding of Rule 10b-5's reliance requirement" be changed, ibid., I prefer that such changes come from Congress in amending § 10(b). The Congress, with its superior resources and expertise, is far better equipped than the federal courts for the task of determining how modern economic theory and global financial markets require that established legal notions of fraud be modified. In choosing to make these decisions itself, the Court, I fear, embarks on a course that it does not genuinely understand, giving rise to consequences it cannot foresee.^[5]

For while the economists' theories which underpin the fraud-on-the-market presumption may have the appeal of mathematical exactitude and scientific certainty, they are — in the end — nothing more than theories which may or may not prove accurate upon further consideration. Even the most earnest advocates of economic analysis of the law recognize this. See, e. g., Easterbrook, Afterword: Knowledge and Answers, 85 Colum. L. Rev. 1117, 1118 (1985). Thus, while the majority states that, for purposes of reaching its result it need only make modest assumptions about the way in which "market professionals generally" do their jobs, and how the conduct of market professionals affects stock prices, ante, at 246, n. 23, I doubt that we are in much of a position [255] to assess which theories aptly describe the functioning of the securities industry.

Consequently, I cannot join the Court in its effort to reconfigure the securities laws, based on recent economic theories, to better fit what it perceives to be the new realities of financial markets. I would leave this task to others more equipped for the job than we.

C

At the bottom of the Court's conclusion that the fraud-on-the-market theory sustains a presumption of reliance is the assumption that individuals rely "on the integrity of the market price" when buying or selling stock in "impersonal, well-developed market[s] for securities." Ante, at 247. Even if I was prepared to accept (as a matter of common sense or general understanding) the assumption that most persons buying or selling stock do so in response to the market price, the fraud-on-the-market theory goes further. For in adopting a "presumption of reliance," the Court also assumes that buyers and sellers rely — not just on the market price — but on the "integrity" of that price. It is this aspect of the fraud-on-the-market hypothesis which most mystifies me.

To define the term "integrity of the market price," the majority quotes approvingly from cases which suggest that investors are entitled to " `rely on the price of a stock as a reflection of its value.' " Ante, at 244 (quoting Peil v. Speiser, 806 F. 2d 1154, 1161 (CA3 1986)). But the meaning of this phrase eludes me, for it implicitly suggests that stocks have some "true value" that is measurable by a standard other than their market price. While the scholastics of medieval times professed a means to make such a valuation of a commodity's "worth,"^[6] I doubt that the federal courts of our day are similarly equipped.

[256] Even if securities had some "value" — knowable and distinct from the market price of a stock — investors do not always share the Court's presumption that a stock's price is a "reflection of [this] value." Indeed, "many investors purchase or sell stock because they believe the price inaccurately reflects the corporation's worth." See Black, Fraud on the Market: A Criticism of Dispensing with Reliance Requirements in Certain Open Market Transactions, 62 N. C. L. Rev. 435, 455 (1984) (emphasis added). If investors really believed that stock prices reflected a stock's "value," many sellers would never sell, and many buyers never buy (given the time and cost associated with executing a stock transaction). As we recognized just a few years ago: "[I]nvestors act on inevitably incomplete or inaccurate information, [consequently] there are always winners and losers; but those who have `lost' have not necessarily been defrauded." Dirks v. SEC, 463 U. S. 646, 667, n. 27 (1983). Yet today, the Court allows investors to recover who can show little more than that they sold stock at a lower price than what might have been.^[7]

I do not propose that the law retreat from the many protections that § 10(b) and Rule 10b-5, as interpreted in our prior cases, provide to investors. But any extension of these laws, to approach something closer to an investor insurance [257] scheme, should come from Congress, and not from the courts.

II

Congress has not passed on the fraud-on-the-market theory the Court embraces today. That is reason enough for us to abstain from doing so. But it is even more troubling that, to the extent that any view of Congress on this question can be inferred indirectly, it is contrary to the result the majority reaches.

A

In the past, the scant legislative history of § 10(b) has led us to look at Congress' intent in adopting other portions of the Securities Exchange Act when we endeavor to discern the limits of private causes of action under Rule 10b-5. See, e. g., Ernst & Ernst v. Hochfelder, 425 U. S. 185, 204-206 (1976). A similar undertaking here reveals that Congress flatly rejected a proposition analogous to the fraud-on-the-market theory in adopting a civil liability provision of the 1934 Act.

Section 18 of the Act expressly provides for civil liability for certain misleading statements concerning securities. See 15 U. S. C. § 78r(a). When the predecessor of this section was first being considered by Congress, the initial draft of the provision allowed recovery by any plaintiff "who shall have purchased or sold a security the price of which may have been affected by such [misleading] statement." See S. 2693, 73d Cong., 2d Sess., § 17(a) (1934). Thus, as initially drafted, the precursor to the express civil liability provision of the 1934 Act would have permitted suits by plaintiffs based solely on the fact that the price of the securities they bought or sold was affected by a misrepresentation: a theory closely akin to the Court's holding today.

Yet this provision was roundly criticized in congressional hearings on the proposed Securities Exchange Act, because it failed to include a more substantial "reliance" requirement.^[8] [258] Subsequent drafts modified the original proposal, and included an express reliance requirement in the final version of the Act. In congressional debates over the redrafted version of this bill, the then-Chairman of the House Committee, Representative Sam Rayburn, explained that the "bill as originally written was very much challenged on the ground that reliance should be required. This objection has been met." 78 Cong. Rec. 7701 (1934). Moreover, in a previous case concerning the scope of § 10(b) and Rule 10b-5, we quoted approvingly from the legislative history of this revised provision, which emphasized the presence of a strict reliance requirement as a prerequisite for recovery. See Ernst & Ernst v. Hochfelder, supra, at 206 (citing S. Rep. No. 792, 73d Cong., 2d Sess., 12-13 (1934)).

Congress thus anticipated meaningful proof of "reliance" before civil recovery can be had under the Securities Exchange Act. The majority's adoption of the fraud-on-the-market theory effectively eviscerates the reliance rule in actions brought under Rule 10b-5, and negates congressional intent to the contrary expressed during adoption of the 1934 Act.

B

A second congressional policy that the majority's opinion ignores is the strong preference the securities laws display for widespread public disclosure and distribution to investors of material information concerning securities. This congressionally adopted policy is expressed in the numerous and varied disclosure requirements found in the federal securities [259] law scheme. See, e. g., 15 U. S. C. §§ 78m, 78o(d) (1982 ed. and Supp. IV).

Yet observers in this field have acknowledged that the fraud-on-the-market theory is at odds with the federal policy favoring disclosure. See, e. g., Black, 62 N. C. L. Rev., at 457-459. The conflict between Congress' preference for disclosure and the fraud-on-the-market theory was well expressed by a jurist who rejected the latter in order to give force to the former:

"[D]isclosure . . . is crucial to the way in which the federal securities laws function. . . . [T]he federal securities laws are intended to put investors into a position from which they can help themselves by relying upon disclosures that others are obligated to make. This system is not furthered by allowing monetary recovery to those who refuse to look out for themselves. If we say that a plaintiff may recover in some circumstances even though he did not read and rely on the defendants' public disclosures, then no one need pay attention to those disclosures and the method employed by Congress to achieve the objective of the 1934 Act is defeated." Shores v. Sklar, 647 F. 2d, at 483 (Randall, J., dissenting).

It is no surprise, then, that some of the same voices calling for acceptance of the fraud-on-the-market theory also favor dismantling the federal scheme which mandates disclosure. But to the extent that the federal courts must make a choice between preserving effective disclosure and trumpeting the new fraud-on-the-market hypothesis, I think Congress has spoken clearly — favoring the current prodisclosure policy. We should limit our role in interpreting § 10(b) and Rule 10b-5 to one of giving effect to such policy decisions by Congress.

III

Finally, the particular facts of this case make it an exceedingly poor candidate for the Court's fraud-on-the-market theory, [260] and illustrate the illogic achieved by that theory's application in many cases.

Respondents here are a class of sellers who sold Basic stock between October 1977 and December 1978, a 14-month period. At the time the class period began, Basic's stock was trading at $20 a share (at the time, an all-time high); the last members of the class to sell their Basic stock got a price of just over $30 a share. App. 363, 423. It is indisputable that virtually every member of the class made money from his or her sale of Basic stock.

The oddities of applying the fraud-on-the-market theory in this case are manifest. First, there are the facts that the plaintiffs are sellers and the class period is so lengthy — both are virtually without precedent in prior fraud-on-the-market cases.^[9] For reasons I discuss in the margin, I think these two facts render this case less apt to application of the fraud-on-the-market hypothesis.

Second, there is the fact that in this case, there is no evidence that petitioner Basic's officials made the troublesome misstatements for the purpose of manipulating stock prices, or with any intent to engage in underhanded trading of Basic stock. Indeed, during the class period, petitioners do not [261] appear to have purchased or sold any Basic stock whatsoever. App. to Pet. for Cert. 27a. I agree with amicus who argues that "[i]mposition of damages liability under Rule 10b-5 makes little sense . . . where a defendant is neither a purchaser nor a seller of securities." See Brief for American Corporate Counsel Association as Amicus Curiae 13. In fact, in previous cases, we had recognized that Rule 10b-5 is concerned primarily with cases where the fraud is committed by one trading the security at issue. See, e. g., Blue Chip Stamps v. Manor Drug Stores, 421 U. S. 723, 736, n. 8 (1975). And it is difficult to square liability in this case with § 10(b)'s express provision that it prohibits fraud "in connection with the purchase or sale of any security." See 15 U. S. C. § 78j(b) (emphasis added).

Third, there are the peculiarities of what kinds of investors will be able to recover in this case. As I read the District Court's class certification order, App. to Pet. for Cert. 123a-126a; ante, at 228-229, n. 5, there are potentially many persons who did not purchase Basic stock until after the first false statement (October 1977), but who nonetheless will be able to recover under the Court's fraud-on-the-market theory. Thus, it is possible that a person who heard the first corporate misstatement and disbelieved it — i. e., someone who purchased Basic stock thinking that petitioners' statement was false — may still be included in the plaintiff-class on remand. How a person who undertook such a speculative stock-investing strategy — and made $10 a share doing so (if he bought on October 22, 1977, and sold on December 15, 1978) — can say that he was "defrauded" by virtue of his reliance on the "integrity" of the market price is beyond me.^[10] [262] And such speculators may not be uncommon, at least in this case. See App. to Pet. for Cert. 125a.

Indeed, the facts of this case lead a casual observer to the almost inescapable conclusion that many of those who bought or sold Basic stock during the period in question flatly disbelieved the statements which are alleged to have been "materially misleading." Despite three statements denying that merger negotiations were underway, Basic stock hit record-high after record-high during the 14-month class period. It seems quite possible that, like Casca's knowing disbelief of Caesar's "thrice refusal" of the Crown,^[11] clever investors were skeptical of petitioners' three denials that merger talks were going on. Yet such investors, the saviest of the savvy, will be able to recover under the Court's opinion, as long as they now claim that they believed in the "integrity of the market price" when they sold their stock (between September and December 1978).^[12] Thus, persons who bought after hearing and relying on the falsity of petitioners' statements may be able to prevail and recover money damages on remand.

And who will pay the judgments won in such actions? I suspect that all too often the majority's rule will "lead to large judgments, payable in the last analysis by innocent investors, for the benefit of speculators and their lawyers." Cf. SEC v. Texas Gulf Sulphur Co., 401 F. 2d 833, 867 (CA2 1968) (en banc) (Friendly, J., concurring), cert. denied, 394 U. S. 976 (1969). This Court and others have previously recognized that "inexorably broadening . . . the class of plaintiff[s] who may sue in this area of the law will ultimately result in more harm than good." Blue Chip Stamps v. Manor Drug Stores, supra, at 747-748. See also Ernst & Ernst v. Hochfelder, 425 U. S., at 214; Ultramares Corp. v. Touche, [263] 255 N. Y. 170, 179-180, 174 N. E. 441, 444-445 (1931) (Cardozo, C. J.). Yet such a bitter harvest is likely to be the reaped from the seeds sewn by the Court's decision today.

IV

In sum, I think the Court's embracement of the fraud-on-the-market theory represents a departure in securities law that we are ill suited to commence — and even less equipped to control as it proceeds. As a result, I must respectfully dissent.

----------

[*] Briefs of amici curiae urging reversal were filed for the American Corporate Counsel Association by Stephen M. Shapiro, Andrew L. Frey, Kenneth S. Geller, Daniel Harris, and Mark I. Levy; for Arthur Andersen & Co. et al. by Victor M. Earle III, Carl D. Liggio, Donald Dreyfus, Harris J. Amhowitz, Kenneth H. Lang, Richard H. Murray, Leonard P. Novello, and Eldon Olson; and for the American Institute of Certified Public Accountants by Louis A. Craco.

[1] In what are known as the Kaiser-Lavino proceedings, the Federal Trade Commission took the position in 1976 that basic or chemical refractories were in a market separate from nonbasic or acidic or alumina refractories; this would remove the antitrust barrier to a merger between Basic and Combustion's refractories subsidiary. On October 12, 1978, the Initial Decision of the Administrative law Judge confirmed that position. See In re Kaiser Aluminum & Chemical Corp., 93 F. T. C. 764, 771, 809-810 (1979). See also the opinion of the Court of Appeals in this case, 786 F. 2d 741, 745 (CA6 1986).

[2] In addition to Basic itself, petitioners are individuals who had been members of its board of directors prior to 1979: Anthony M. Caito, Samuel Eels, Jr., John A. Gelbach, Harley C. Lee, Max Muller, H. Chapman Rose, Edmund G. Sylvester, and John C. Wilson, Jr. Another former director, Mathew J. Ludwig, was a party to the proceedings below but died on July 17, 1986, and is not a petitioner here. See Brief for Petitioners ii.

[3] In light of our disposition of this case, any further characterization of these discussions must await application, on remand, of the materiality standard adopted today.

[4] On October 21, 1977, after heavy trading and a new high in Basic stock, the following news item appeared in the Cleveland Plain Dealer:

"[Basic] President Max Muller said the company knew no reason for the stock's activity and that no negotiations were under way with any company for a merger. He said Flintkote recently denied Wall Street rumors that it would make a tender offer of $25 a share for control of the Cleveland-based maker of refractories for the steel industry." App. 363.

On September 25, 1978, in reply to an inquiry from the New York Stock Exchange, Basic issued a release concerning increased activity in its stock and stated that

"management is unaware of any present or pending company development that would result in the abnormally heavy trading activity and price fluctuation in company shares that have been experienced in the past few days." Id., at 401.

On November 6, 1978, Basic issued to its shareholders a "Nine Months Report 1978." This Report stated:

"With regard to the stock market activity in the Company's shares we remain unaware of any present or pending developments which would account for the high volume of trading and price fluctuations in recent months." Id., at 403.

[5] Respondents initially sought to represent all those who sold Basic shares between October 1, 1976, and December 20, 1978. See Amended Complaint in No. C79-1220 (ND Ohio), ¶ 5. The District Court, however, recognized a class period extending only from October 21, 1977, the date of the first public statement, rather than from the date negotiations allegedly commenced. In its certification decision, as subsequently amended, the District Court also excluded from the class those who had purchased Basic shares after the October 1977 statement but sold them before the September 1978 statement, App. to Pet. for Cert. 123a-124a, and those who sold their shares after the close of the market on Friday, December 15, 1978. Id., at 137a.

[6] In relevant part, Rule 10b-5 provides:

"It shall be unlawful for any person, directly or indirectly, by the use of any means or instrumentality of interstate commerce, or of the mails or of any facility of any national securities exchange,

.....

"(b) To make any untrue statement of a material fact or to omit to state a material fact necessary in order to make the statements made, in the light of the circumstances under which they were made, not misleading . . . ,

.....

"in connection with the purchase or sale of any security."

[7] TSC Industries arose under § 14(a), as amended, of the 1934 Act, 15 U. S. C. § 78n(a), and Rule 14a-9, 17 CFR § 240.14a-9 (1975).

[8] This application of the § 14(a) definition of materiality to § 10(b) and Rule 10b-5 is not disputed. See Brief for Petitioners 17, n. 12; Brief for Respondents 30, n. 10; Brief for SEC as Amicus Curiae 8, n. 4. See also McGrath v. Zenith Radio Corp., 651 F. 2d 458, 466, n. 4 (CA7), cert. denied, 454 U. S. 835 (1981), and Goldberg v. Meridor, 567 F. 2d 209, 218-219 (CA2 1977), cert. denied, 434 U. S. 1069 (1978).

[9] We do not address here any other kinds of contingent or speculative information, such as earnings forecasts or projections. See generally Hiler, The SEC and the Courts' Approach to Disclosure of Earnings Projections, Asset Appraisals, and Other Soft Information: Old Problems, Changing Views, 46 Md. L. Rev. 1114 (1987).

[10] See Staffin v. Greenberg, 672 F. 2d 1196, 1207 (CA3 1982) (defining duty to disclose existence of ongoing merger negotiations as triggered when agreement-in-principle is reached); Greenfield v. Heublein, Inc., 742 F. 2d 751 (CA3 1984) (applying agreement-in-principle test to materiality inquiry), cert. denied, 469 U. S. 1215 (1985). Citing Staffin, the United States Court of Appeals for the Second Circuit has rejected a claim that defendant was under an obligation to disclose various events related to merger negotiations. Reiss v. Pan American World Airways, Inc., 711 F. 2d 11, 13-14 (1983). The Seventh Circuit recently endorsed the agreement-in-principle test of materiality. See Flamm v. Eberstadt, 814 F. 2d 1169, 1174-1179 (describing agreement-in-principle as an agreement on price and structure), cert. denied, 484 U. S. 853 (1987). In some of these cases it is unclear whether the court based its decision on a finding that no duty arose to reveal the existence of negotiations, or whether it concluded that the negotiations were immaterial under an interpretation of the opinion in TSC Industries, Inc. v. Northway, Inc., 426 U. S. 438 (1976).

[11] Reasoning backwards from a goal of economic efficiency, that Court of Appeals stated: "Rule 10b-5 is about fraud, after all, and it is not fraudulent to conduct business in a way that makes investors better off . . . ." 814 F. 2d, at 1177.

[12] See, e. g., Brown, Corporate Secrecy, the Federal Securities Laws, and the Disclosure of Ongoing Negotiations, 36 Cath. U. L. Rev. 93, 145-155 (1986); Bebchuk, The Case for Facilitating Competing Tender Offers, 95 Harv. L. Rev. 1028 (1982); Flamm v. Eberstadt, 814 F. 2d, at 1177, n. 2 (citing scholarly debate). See also In re Carnation Co., Exchange Act Release No. 22214, 33 S. E. C. Docket 1025, 1030 (1985) ("The importance of accurate and complete issuer disclosure to the integrity of the securities markets cannot be overemphasized. To the extent that investors cannot rely upon the accuracy and completeness of issuer statements, they will be less likely to invest, thereby reducing the liquidity of the securities markets to the detriment of investors and issuers alike").

[13] See SEC v. Texas Gulf Sulphur Co., 401 F. 2d 833, 862 (CA2 1968) (en banc) ("Rule 10b-5 is violated whenever assertions are made, as here, in a manner reasonably calculated to influence the investing public . . . if such assertions are false or misleading or are so incomplete as to mislead . . ."), cert. denied sub nom. Coates v. SEC, 394 U. S. 976 (1969).

[14] "Although the Committee believes that ideally it would be desirable to have absolute certainty in the application of the materiality concept, it is its view that such a goal is illusory and unrealistic. The materiality concept is judgmental in nature and it is not possible to translate this into a numerical formula. The Committee's advice to the [SEC] is to avoid this quest for certainty and to continue consideration of materiality on a case-by-case basis as disclosure problems are identified." House Committee on Interstate and Foreign Commerce, Report of the Advisory Committee on Corporate Disclosure to the Securities and Exchange Commission, 95th Cong., 1st Sess., 327 (Comm. Print 1977).

[15] Subsequently, the Sixth Circuit denied a petition for rehearing en banc in this case. App. to Pet. for Cert. 144a. Concurring separately, Judge Wellford, one of the original panel members, then explained that he did not read the panel's opinion to create a "conclusive presumption of materiality for any undisclosed information claimed to render inaccurate statements denying the existence of alleged preliminary merger discussions." Id., at 145a. In his view, the decision merely reversed the District Court's judgment, which had been based on the agreement-in-principle standard. Ibid.

[16] The SEC in the present case endorses the highly fact-dependent probability/magnitude balancing approach of Texas Gulf Sulphur. It explains: "The possibility of a merger may have an immediate importance to investors in the company's securities even if no merger ultimately takes place." Brief for SEC as Amicus Curiae 10. The SEC's insights are helpful, and we accord them due deference. See TSC Industries, Inc. v. Northway, Inc., 426 U. S., at 449, n. 10.

[17] To be actionable, of course, a statement must also be misleading. Silence, absent a duty to disclose, is not misleading under Rule 10b-5. "No comment" statements are generally the functional equivalent of silence. See In re Carnation Co., Exchange Act Release No. 22214, 33 S. E. C. Docket 1025 (1985). See also New York Stock Exchange Listed Company Manual § 202.01, reprinted in 3 CCH Fed. Sec. L. Rep. ¶ 23,515 (1987) (premature public announcement may properly be delayed for valid business purpose and where adequate security can be maintained); American Stock Exchange Company Guide §§ 401-405, reprinted in 3 CCH Fed. Sec. L. Rep. ¶¶ 23,124A-23, 124E (1985) (similar provisions).

It has been suggested that given current market practices, a "no comment" statement is tantamount to an admission that merger discussions are underway. See Flamm v. Eberstadt, 814 F. 2d, at 1178. That may well hold true to the extent that issuers adopt a policy of truthfully denying merger rumors when no discussions are underway, and of issuing "no comment" statements when they are in the midst of negotiations. There are, of course, other statement policies firms could adopt; we need not now advise issuers as to what kind of practice to follow, within the range permitted by law. Perhaps more importantly, we think that creating an exception to a regulatory scheme founded on a prodisclosure legislative philosophy, because complying with the regulation might be "bad for business," is a role for Congress, not this Court. See also id., at 1182 (opinion concurring in judgment and concurring in part).

[18] We find no authority in the statute, the legislative history, or our previous decisions for varying the standard of materiality depending on who brings the action or whether insiders are alleged to have profited. See, e. g., Pavlidis v. New England Patriots Football Club, Inc., 737 F. 2d 1227, 1231 (CA1 1984) ("A fact does not become more material to the shareholder's decision because it is withheld by an insider, or because the insider might profit by withholding it"); cf. Aaron v. SEC, 446 U. S. 680, 691 (1980) ("[S]cienter is an element of a violation of § 10(b) and Rule 10b-5, regardless of the identity of the plaintiff or the nature of the relief sought").

We recognize that trading (and profit making) by insiders can serve as an indication of materiality, see SEC v. Texas Gulf Sulphur Co., 401 F. 2d, at 851; General Portland, Inc. v. LaFarge Coppee S. A., [1982-1983] CCH Fed. Sec. L. Rep. ¶ 99,148, p. 95,544 (ND Tex. 1981). We are not prepared to agree, however, that "[i]n cases of the disclosure of inside information to a favored few, determination of materiality has a different aspect than when the issue is, for example, an inaccuracy in a publicly disseminated press release." SEC v. Geon Industries, Inc., 531 F. 2d 39, 48 (CA2 1976). Devising two different standards of materiality, one for situations where insiders have traded in abrogation of their duty to disclose or abstain (or for that matter when any disclosure duty has been breached), and another covering affirmative misrepresentations by those under no duty to disclose (but under the ever-present duty not to mislead), would effectively collapse the materiality requirement into the analysis of defendant's disclosure duties.

[19] See, e. g., SEC v. Shapiro, 494 F. 2d 1301, 1306-1307 (CA2 1974) (in light of projected very substantial increase in earnings per share, negotiations material, although merger still less than probable); Holmes v. Bateson, 583 F. 2d 542, 558 (CA1 1978) (merger negotiations material although they had not yet reached point of discussing terms); SEC v. Gaspar, [1984-1985] CCH Fed. Sec. L. Rep. ¶ 92,004, pp. 90,977-90,978 (SDNY 1985) (merger negotiations material although they did not proceed to actual tender offer); Dungan v. Colt Industries, Inc., 532 F. Supp. 832, 837 (ND Ill. 1982) (fact that defendants were seriously exploring the sale of their company was material); American General Ins. Co. v. Equitable General Corp., 493 F. Supp. 721, 744-745 (ED Va. 1980) (merger negotiations material four months before agreement-in-principle reached). Cf. Susquehanna Corp. v. Pan American Sulphur Co., 423 F. 2d 1075, 1084-1085 (CA5 1970) (holding immaterial "unilateral offer to negotiate" never acknowledged by target and repudiated two days later); Berman v. Gerber Products Co., 454 F. Supp. 1310, 1316, 1318 (WD Mich. 1978) (mere "overtures" immaterial).

[20] The Sixth Circuit rejected the District Court's narrow reading of Basic's "no developments" statement, see n. 4, supra, which focused on whether petitioners knew of any reason for the activity in Basic stock, that is, whether petitioners were aware of leaks concerning ongoing discussions. 786 F. 2d, at 747. See also Comment, Disclosure of Preliminary Merger Negotiations Under Rule 10b-5, 62 Wash. L. Rev. 81, 82-84 (1987) (noting prevalence of leaks and studies demonstrating that substantial trading activity immediately preceding merger announcements is the "rule, not the exception"). We accept the Court of Appeals' reading of the statement as the more natural one, emphasizing management's knowledge of developments (as opposed to leaks) that would explain unusual trading activity. See id., at 92-93; see also SEC v. Texas Gulf Sulphur Co., 401 F. 2d, at 862-863.

[21] W. Keeton, D. Dobbs, R. Keeton, & D. Owen, Prosser and Keeton on Law of Torts 726 (5th ed. 1984) ("The reasons for the separate development of [the tort action for misrepresentation and nondisclosure], and for its peculiar limitations, are in part historical, and in part connected with the fact that in the great majority of the cases which have come before the courts the misrepresentations have been made in the course of a bargaining transaction between the parties. Consequently the action has been colored to a considerable extent by the ethics of bargaining between distrustful adversaries") (footnote omitted).

[22] Actions under Rule 10b-5 are distinct from common-law deceit and misrepresentation claims, see Blue Chip Stamps v. Manor Drug Stores, 421 U. S. 723, 744-745 (1975), and are in part designed to add to the protections provided investors by the common law, see Herman & MacLean v. Huddleston, 459 U. S. 375, 388-389 (1983).

[23] Contrary to the dissent's suggestion, the incentive for investors to "pay attention" to issuers' disclosures comes from their motivation to make a profit, not their attempt to preserve a cause of action under Rule 10b-5. Facilitating an investor's reliance on the market, consistently with Congress' expectations, hardly calls for "dismantling the federal scheme which mandates disclosure." See post, at 259.

[24] See In re LTV Securities Litigation, 88 F. R. D. 134, 144 (ND Tex. 1980) (citing studies); Fischel, Use of Modern Finance Theory in Securities Fraud Cases Involving Actively Traded Securities, 38 Bus. Law. 1, 4, n. 9 (1982) (citing literature on efficient-capital-market theory); Dennis, Materiality and the Efficient Capital Market Model: A Recipe for the Total Mix. 25 Wm. & Mary L. Rev. 373, 374-381, and n. 1 (1984). We need not determine by adjudication what economists and social scientists have debated through the use of sophisticated statistical analysis and the application of economic theory. For purposes of accepting the presumption of reliance in this case, we need only believe that market professionals generally consider most publicly announced material statements about companies, thereby affecting stock market prices.

[25] See, e. g., Peil v. Speiser, 806 F. 2d 1154, 1161 (CA3 1986); Harris v. Union Electric Co., 787 F. 2d 355, 367, and n. 9 (CA8), cert. denied, 479 U. S. 823 (1986); Lipton v. Documation, Inc., 734 F. 2d 740 (CA11 1984), cert. denied, 469 U. S. 1132 (1985); T. J. Raney & Sons, Inc. v. Fort Cobb, Oklahoma Irrigation Fuel Authority, 717 F. 2d 1330, 1332-1333 (CA10 1983), cert. denied sub nom. Linde, Thomson, Fairchild, Langworthy, Kohn & Van Dyke v. T. J. Raney & Sons, Inc., 465 U. S. 1026 (1984); Panzirer v. Wolf, 663 F. 2d 365, 367-368 (CA2 1981), vacated and remanded sub nom. Price Waterhouse v. Panzirer, 459 U. S. 1027 (1982); Ross v. A. H. Robins Co., 607 F. 2d 545, 553 (CA2 1979), cert. denied, 446 U. S. 946 (1980); Blackie v. Barrack, 524 F. 2d 891, 905-908 (CA9 1975), cert. denied, 429 U. S. 816 (1976).

[26] See, e. g., Black, Fraud on the Market: A Criticism of Dispensing with Reliance Requirements in Certain Open Market Transactions, 62 N. C. L. Rev. 435 (1984); Note, The Fraud-on-the-Market Theory, 95 Harv. L. Rev. 1143 (1982); Note, Fraud on the Market: An Emerging Theory of Recovery Under SEC Rule 10b-5, 50 Geo. Wash. L. Rev. 627 (1982).

[27] The Court of Appeals held that in order to invoke the presumption, a plaintiff must allege and prove: (1) that the defendant made public misrepresentations; (2) that the misrepresentations were material; (3) that the shares were traded on an efficient market; (4) that the misrepresentations would induce a reasonable, relying investor to misjudge the value of the shares; and (5) that the plaintiff traded the shares between the time the misrepresentations were made and the time the truth was revealed. See 786 F. 2d, at 750.

Given today's decision regarding the definition of materiality as to preliminary merger discussions, elements (2) and (4) may collapse into one.

[28] By accepting this rebuttable presumption, we do not intend conclusively to adopt any particular theory of how quickly and completely publicly available information is reflected in market price. Furthermore, our decision today is not to be interpreted as addressing the proper measure of damages in litigation of this kind.

[29] We note there may be a certain incongruity between the assumption that Basic shares are traded on a well-developed, efficient, and information-hungry market, and the allegation that such a market could remain misinformed, and its valuation of Basic shares depressed, for 14 months, on the basis of the three public statements. Proof of that sort is a matter for trial, throughout which the District Court retains the authority to amend the certification order as may be appropriate. See Fed. Rules Civ. Proc. 23(c)(1) and (c)(4). See 7B C. Wright, A. Miller, & M. Kane, Federal Practice and Procedure 128-132 (1986). Thus, we see no need to engage in the kind of factual analysis the dissent suggests that manifests the "oddities" of applying a rebuttable presumption of reliance in this case. See post, at 259-263.

----------

[1] The earliest Court of Appeals case adopting this theory cited by the Court is Blackie v. Barrack, 524 F. 2d 891 (CA9 1975), cert. denied, 429 U. S. 816 (1976). Moreover, widespread acceptance of the fraud-on-the-market theory in the Courts of Appeals cannot be placed any earlier than five or six years ago. See ante, at 246-247, n. 24; Brief for Securities and Exchange Commission as Amicus Curiae 21, n. 24.

[2] See, e. g., Zweig v. Hearst Corp., 594 F. 2d 1261, 1268-1271 (CA9 1979); Arthur Young & Co. v. United States District Court, 549 F. 2d 686, 694-695 (CA9), cert. denied, 434 U. S. 829 (1977); Pellman v. Cinerama, Inc., 89 F. R. D. 386, 388 (SDNY 1981).

[3] Cases illustrating these factual situations are, respectively, Zweig v. Hearst Corp., supra, at 1271 (Ely, J., dissenting); Abrams v. Johns-Manville Corp., [1981-1982] CCH Fed. Sec. L. Rep. ¶ 98,348, p. 92,157 (SDNY 1981); Fausett v. American Resources Management Corp., 542 F. Supp. 1234, 1238-1239 (Utah 1982).

The Abrams decision illustrates the particular pliability of the fraud-on-the-market presumption. In Abrams, the plaintiff represented a class of purchasers of defendant's stock who were allegedly misled by defendant's misrepresentations in annual reports. But in a deposition taken shortly after the plaintiff filed suit, she testified that she had bought defendant's stock primarily because she thought that favorable changes in the Federal Tax Code would boost sales of its product (insulation).

Two years later, after the defendant moved for summary judgment based on the plaintiff's failure to prove reliance on the alleged misrepresentations, the plaintiff resuscitated her case by executing an affidavit which stated that she "certainly [had] assumed that the market price of Johns-Manville stock was an accurate reflection of the worth of the company" and would not have paid the then-going price if she had known otherwise. Abrams, supra, at 92,157. Based on this affidavit, the District Court permitted the plaintiff to proceed on her fraud-on-the-market theory.

Thus, Abrams demonstrates how easily a post hoc statement will enable a plaintiff to bring a fraud-on-the-market action — even in the rare case where a plaintiff is frank or foolhardy enough to admit initially that a factor other than price led her to the decision to purchase a particular stock.

[4] This view was put well by two commentators who wrote a few years ago:

"Of all recent developments in financial economics, the efficient capital market hypothesis (`ECMH') has achieved the widest acceptance by the legal culture. . . .

"Yet the legal culture's remarkably rapid and broad acceptance of an economic concept that did not exist twenty years ago is not matched by an equivalent degree of understanding." Gilson & Kraakman, The Mechanisms of Market Efficiency, 70 Va. L. Rev. 549, 549-550 (1984) (footnotes omitted; emphasis added).

While the fraud-on-the-market theory has gained even broader acceptance since 1984, I doubt that it has achieved any greater understanding.

[5] For example, Judge Posner in his Economic Analysis of Law § 15.8, pp. 423-424 (3d ed. 1986), submits that the fraud-on-the-market theory produces the "economically correct result" in Rule 10b-5 cases but observes that the question of damages under the theory is quite problematic. Not withstanding the fact that "[a]t first blush it might seem obvious," the proper calculation of damages when the fraud-on-the-market theory is applied must rest on several "assumptions" about "social costs" which are "difficult to quantify." Ibid. Of course, answers to the question of the proper measure of damages in a fraud-on-the-market case are essential for proper implementation of the fraud-on-the-market presumption. Not surprisingly, the difficult damages question is one the Court expressly declines to address today. Ante, at 248, n. 27.

[6] See E. Salin, Just Price, 8 Encyclopaedia of Social Sciences 504-506 (1932); see also R. de Roover, Economic Thought: Ancient and Medieval Thought, 4 International Encyclopedia of Social Sciences 433-435 (1968).

[7] This is what the Court's rule boils down to in practical terms. For while, in theory, the Court allows for rebuttal of its "presumption of reliance" — a proviso with which I agree, see supra, at 251 — in practice the Court must realize, as other courts applying the fraud-on-the-market theory have, that such rebuttal is virtually impossible in all but the most extraordinary case. See Blackie v. Barrack, 524 F. 2d, at 906-907, n. 22; In re LTV Securities Litigation, 88 F. R. D. 134, 143, n. 4 (ND Tex. 1980).

Consequently, while the Court considers it significant that the fraud-on-the-market presumption it endorses is a rebuttable one, ante, at 242, 248, the majority's implicit rejection of the "pure causation" fraud-on-the-market theory rings hollow. In most cases, the Court's theory will operate just as the causation theory would, creating a nonrebuttable presumption of "reliance" in future Rule 10b-5 actions.

[8] See Stock Exchange Practices, Hearings on S. Res. 84, 56, and 97 before the Senate Committee on Banking and Currency, 73d Cong., 2d Sess., pt. 15, p. 6638 (1934) (statement of Richard Whitney, President of the New York Stock Exchange); Stock Exchange Regulation, Hearing on H. R. 7852 and 8720, before the House Committee on Interstate and Foreign Commerce, 73d Cong., 2d Sess., 226 (1934) (statement of Richard Whitney).

[9] None of the Court of Appeals cases the Court cites as endorsing the fraud-on-the-market theory, ante, at 246-247, n. 24, involved seller-plaintiffs. Rather, all of these cases were brought by purchasers who bought securities in a short period following some material misstatement (or similar act) by an issuer, which was alleged to have falsely inflated a stock's price.

Even if the fraud-on-the-market theory provides a permissible link between such a misstatement and a decision to purchase a security shortly thereafter, surely that link is far more attenuated between misstatements made in October 1977, and a decision to sell a stock the following September, 11 months later. The fact that the plaintiff-class is one of sellers, and that the class period so long, distinguish this case from any other cited in the Court's opinion, and make it an even poorer candidate for the fraud-on-the-market presumption. Cf., e. g., Schlanger v. Four-Phase Systems Inc., 555 F. Supp. 535 (SDNY 1982) (permitting class of sellers to use fraud-on-the-market theory where the class period was eight days long).

[10] The Court recognizes that a person who sold his Basic shares believing petitioners' statements to be false may not be entitled to recovery. Ante, at 249. Yet it seems just as clear to me that one who bought Basic stock under this same belief — hoping to profit from the uncertainty over Basic's merger plans — should not be permitted to recover either.

[11] See W. Shakespeare, Julius Caesar, Act I, Scene II.

[12] The ease with which such a post hoc claim of "reliance on the integrity of the market price" can be made, and gain acceptance by a trial court, is illustrated by Abrams v. Johns-Manville Corp., discussed in n. 3, supra.

CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR THE EIGHTH CIRCUIT

[643] [644] [645] [646] Ginsburg, J., delivered the opinion of the Court, in which Stevens, O'Connor, Kennedy, Souter, and Breyer, JJ., joined, and in which Scalia, J., joined as to Parts I, III, and IV. Scalia, J., filed an opinion concurring in part and dissenting in part, post, p. 679. Thomas, J., filed an opinion concurring in the judgment in part and dissenting in part, in which Rehnquist, C. J., joined, post, p. 680.

Deputy Solicitor General Dreeben argued the cause for the United States. With him on the briefs were Acting Solicitor General Dellinger, Acting Assistant Attorney General Richard, Paul R. Q. Wolfson, Joseph C. Wyderko, Richard H. Walker, Paul Gonson, Jacob H. Stillman, Eric Summergrad, and Randall W. Quinn.

John D. French argued the cause for respondent. With him on the brief was Elizabeth L. Taylor.^[1]

Justice Ginsburg, delivered the opinion of the Court.

This case concerns the interpretation and enforcement of § 10(b) and § 14(e) of the Securities Exchange Act of 1934, and rules made by the Securities and Exchange Commission pursuant to these provisions, Rule 10b—5 and Rule 14e—3(a). [647] Two prime questions are presented. The first relates to the misappropriation of material, nonpublic information for securities trading; the second concerns fraudulent practices in the tender offer setting. In particular, we address and resolve these issues: (1) Is a person who trades in securities for personal profit, using confidential information misappropriated in breach of a fiduciary duty to the source of the information, guilty of violating § 10(b) and Rule 10b—5? (2) Did the Commission exceed its rulemaking authority by adopting Rule 14e—3(a), which proscribes trading on undisclosed information in the tender offer setting, even in the absence of a duty to disclose? Our answer to the first question is yes, and to the second question, viewed in the context of this case, no.

I

Respondent James Herman O'Hagan was a partner in the law firm of Dorsey & Whitney in Minneapolis, Minnesota. In July 1988, Grand Metropolitan PLC (Grand Met), a company based in London, England, retained Dorsey & Whitney as local counsel to represent Grand Met regarding a potential tender offer for the common stock of the Pillsbury Company, headquartered in Minneapolis. Both Grand Met and Dorsey & Whitney took precautions to protect the confidentiality of Grand Met's tender offer plans. O'Hagan did no work on the Grand Met representation. Dorsey & Whitney withdrew from representing Grand Met on September 9, 1988. Less than a month later, on October 4, 1988, Grand Met publicly announced its tender offer for Pillsbury stock.

On August 18, 1988, while Dorsey & Whitney was still representing Grand Met, O'Hagan began purchasing call options for Pillsbury stock. Each option gave him the right to purchase 100 shares of Pillsbury stock by a specified date in September 1988. Later in August and in September, O'Hagan made additional purchases of Pillsbury call options. By the end of September, he owned 2,500 unexpired Pillsbury options, apparently more than any other individual investor. [648] See App. 85, 148. O'Hagan also purchased, in September 1988, some 5,000 shares of Pillsbury common stock, at a price just under $39 per share. When Grand Met announced its tender offer in October, the price of Pillsbury stock rose to nearly $60 per share. O'Hagan then sold his Pillsbury call options and common stock, making a profit of more than $4.3 million.

The Securities and Exchange Commission (SEC or Commission) initiated an investigation into O'Hagan's transactions, culminating in a 57-count indictment. The indictment alleged that O'Hagan defrauded his law firm and its client, Grand Met, by using for his own trading purposes material, nonpublic information regarding Grand Met's planned tender offer. Id., at 8.^[2] According to the indictment, O'Hagan used the profits he gained through this trading to conceal his previous embezzlement and conversion of unrelated client trust funds. Id., at 10.^[3] O'Hagan was charged with 20 counts of mail fraud, in violation of 18 U. S. C. § 1341; 17 counts of securities fraud, in violation of § 10(b) of the Securities Exchange Act of 1934 (Exchange Act), 48 Stat. 891, 15 U. S. C. § 78j(b), and SEC Rule 10b—5, 17 CFR § 240.10b—5 [649] (1996); 17 counts of fraudulent trading in connection with a tender offer, in violation of § 14(e) of the Exchange Act, 15 U. S. C. § 78n(e), and SEC Rule 14e—3(a), 17 CFR § 240.14e— 3(a) (1996); and 3 counts of violating federal money laundering statutes, 18 U. S. C. §§ 1956(a)(1)(B)(i), 1957. See App. 13-24. A jury convicted O'Hagan on all 57 counts, and he was sentenced to a 41-month term of imprisonment.

A divided panel of the Court of Appeals for the Eighth Circuit reversed all of O'Hagan's convictions. 92 F. 3d 612 (1996). Liability under § 10(b) and Rule 10b—5, the Eighth Circuit held, may not be grounded on the "misappropriation theory" of securities fraud on which the prosecution relied. Id., at 622. The Court of Appeals also held that Rule 14e— 3(a)—which prohibits trading while in possession of material, nonpublic information relating to a tender offer—exceeds the SEC's § 14(e) rulemaking authority because the Rule contains no breach of fiduciary duty requirement. Id., at 627. The Eighth Circuit further concluded that O'Hagan's mail fraud and money laundering convictions rested on violations of the securities laws, and therefore could not stand once the securities fraud convictions were reversed. Id., at 627-628. Judge Fagg, dissenting, stated that he would recognize and enforce the misappropriation theory, and would hold that the SEC did not exceed its rulemaking authority when it adopted Rule 14e—3(a) without requiring proof of a breach of fiduciary duty. Id., at 628.

Decisions of the Courts of Appeals are in conflict on the propriety of the misappropriation theory under § 10(b) and Rule 10b—5, see infra this page and 650, and n. 3, and on the legitimacy of Rule 14e—3(a) under § 14(e), see infra, at 669— 670. We granted certiorari, 519 U. S. 1087 (1997), and now reverse the Eighth Circuit's judgment.

II

We address first the Court of Appeals' reversal of O'Hagan's convictions under § 10(b) and Rule 10b—5. Following [650] the Fourth Circuit's lead, see United States v. Bryan, 58 F. 3d 933, 943-959 (1995), the Eighth Circuit rejected the misappropriation theory as a basis for § 10(b) liability. We hold, in accord with several other Courts of Appeals,^[4] that criminal liability under § 10(b) may be predicated on the misappropriation theory.^[5]

A

In pertinent part, § 10(b) of the Exchange Act provides:

"It shall be unlawful for any person, directly or indirectly, by the use of any means or instrumentality of interstate commerce or of the mails, or of any facility of any national securities exchange—

. . . . .

"(b) To use or employ, in connection with the purchase or sale of any security registered on a national securities exchange or any security not so registered, any manipulative or deceptive device or contrivance in contravention of such rules and regulations as the [Securities and Exchange] Commission may prescribe as necessary or appropriate in the public interest or for the protection of investors." 15 U. S. C. § 78j(b). [651] The statute thus proscribes (1) using any deceptive device (2) in connection with the purchase or sale of securities, in contravention of rules prescribed by the Commission. The provision, as written, does not confine its coverage to deception of a purchaser or seller of securities, see United States v. Newman, 664 F. 2d 12, 17 (CA2 1981); rather, the statute reaches any deceptive device used "in connection with the purchase or sale of any security."

Pursuant to its § 10(b) rulemaking authority, the Commission has adopted Rule 10b—5, which, as relevant here, provides:

"It shall be unlawful for any person, directly or indirectly, by the use of any means or instrumentality of interstate commerce, or of the mails or of any facility of any national securities exchange,

"(a) To employ any device, scheme, or artifice to defraud, [or]

. . . . .

"(c) To engage in any act, practice, or course of business which operates or would operate as a fraud or deceit upon any person, "in connection with the purchase or sale of any security." 17 CFR § 240.10b—5 (1996).

Liability under Rule 10b—5, our precedent indicates, does not extend beyond conduct encompassed by § 10(b)'s prohibition. See Ernst & Ernst v. Hochfelder, 425 U. S. 185, 214 (1976) (scope of Rule 10b—5 cannot exceed power Congress granted Commission under § 10(b)); see also Central Bank of Denver, N. A. v. First Interstate Bank of Denver, N. A., 511 U. S. 164, 173 (1994) ("We have refused to allow [private] 10b—5 challenges to conduct not prohibited by the text of the statute.").

Under the "traditional" or "classical theory" of insider trading liability, § 10(b) and Rule 10b—5 are violated when a corporate insider trades in the securities of his corporation [652] on the basis of material, nonpublic information. Trading on such information qualifies as a "deceptive device" under § 10(b), we have affirmed, because "a relationship of trust and confidence [exists] between the shareholders of a corporation and those insiders who have obtained confidential information by reason of their position with that corporation." Chiarella v. United States, 445 U. S. 222, 228 (1980). That relationship, we recognized, "gives rise to a duty to disclose [or to abstain from trading] because of the `necessity of preventing a corporate insider from . . . tak[ing] unfair advantage of . . . uninformed . . . stockholders.' " Id., at 228-229 (citation omitted). The classical theory applies not only to officers, directors, and other permanent insiders of a corporation, but also to attorneys, accountants, consultants, and others who temporarily become fiduciaries of a corporation. See Dirks v. SEC, 463 U. S. 646, 655, n. 14 (1983).

The "misappropriation theory" holds that a person commits fraud "in connection with" a securities transaction, and thereby violates § 10(b) and Rule 10b—5, when he misappropriates confidential information for securities trading purposes, in breach of a duty owed to the source of the information. See Brief for United States 14. Under this theory, a fiduciary's undisclosed, self-serving use of a principal's information to purchase or sell securities, in breach of a duty of loyalty and confidentiality, defrauds the principal of the exclusive use of that information. In lieu of premising liability on a fiduciary relationship between company insider and purchaser or seller of the company's stock, the misappropriation theory premises liability on a fiduciary-turned-trader's deception of those who entrusted him with access to confidential information.

The two theories are complementary, each addressing efforts to capitalize on nonpublic information through the purchase or sale of securities. The classical theory targets a corporate insider's breach of duty to shareholders with whom the insider transacts; the misappropriation theory outlaws [653] trading on the basis of nonpublic information by a corporate "outsider" in breach of a duty owed not to a trading party, but to the source of the information. The misappropriation theory is thus designed to "protec[t] the integrity of the securities markets against abuses by `outsiders' to a corporation who have access to confidential information that will affect th[e] corporation's security price when revealed, but who owe no fiduciary or other duty to that corporation's shareholders." Ibid.

In this case, the indictment alleged that O'Hagan, in breach of a duty of trust and confidence he owed to his law firm, Dorsey & Whitney, and to its client, Grand Met, traded on the basis of nonpublic information regarding Grand Met's planned tender offer for Pillsbury common stock. App. 16. This conduct, the Government charged, constituted a fraudulent device in connection with the purchase and sale of securities.^[6]

B

We agree with the Government that misappropriation, as just defined, satisfies § 10(b)'s requirement that chargeable conduct involve a "deceptive device or contrivance" used "in connection with" the purchase or sale of securities. We observe, first, that misappropriators, as the Government describes them, deal in deception. A fiduciary who "[pretends] loyalty to the principal while secretly converting the principal's information for personal gain," Brief for United States [654] 17, "dupes" or defrauds the principal. See Aldave, Misappropriation: A General Theory of Liability for Trading on Nonpublic Information, 13 Hofstra L. Rev. 101, 119 (1984).

We addressed fraud of the same species in Carpenter v. United States, 484 U. S. 19 (1987), which involved the mail fraud statute's proscription of "any scheme or artifice to defraud," 18 U. S. C. § 1341. Affirming convictions under that statute, we said in Carpenter that an employee's undertaking not to reveal his employer's confidential information "became a sham" when the employee provided the information to his co-conspirators in a scheme to obtain trading profits. 484 U. S., at 27. A company's confidential information, we recognized in Carpenter, qualifies as property to which the company has a right of exclusive use. Id., at 25-27. The undisclosed misappropriation of such information, in violation of a fiduciary duty, the Court said in Carpenter, constitutes fraud akin to embezzlement—"`the fraudulent appropriation to one's own use of the money or goods entrusted to one's care by another.' " Id., at 27 (quoting Grin v. Shine, 187 U. S. 181, 189 (1902)); see Aldave, 13 Hofstra L. Rev., at 119. Carpenter `s discussion of the fraudulent misuse of confidential information, the Government notes, "is a particularly apt source of guidance here, because [the mail fraud statute] (like Section 10(b)) has long been held to require deception, not merely the breach of a fiduciary duty." Brief for United States 18, n. 9 (citation omitted).

Deception through nondisclosure is central to the theory of liability for which the Government seeks recognition. As counsel for the Government stated in explanation of the theory at oral argument: "To satisfy the common law rule that a trustee may not use the property that [has] been entrusted [to] him, there would have to be consent. To satisfy the requirement of the Securities Act that there be no deception, there would only have to be disclosure." Tr. of Oral Arg. 12; see generally Restatement (Second) of Agency §§ 390, 395 [655] (1958) (agent's disclosure obligation regarding use of confidential information).^[7]

The misappropriation theory advanced by the Government is consistent with Santa Fe Industries, Inc. v. Green, 430 U. S. 462 (1977), a decision underscoring that § 10(b) is not an all-purpose breach of fiduciary duty ban; rather, it trains on conduct involving manipulation or deception. See id., at 473-476. In contrast to the Government's allegations in this case, in Santa Fe Industries, all pertinent facts were disclosed by the persons charged with violating § 10(b) and Rule 10b—5, see id., at 474; therefore, there was no deception through nondisclosure to which liability under those provisions could attach, see id., at 476. Similarly, full disclosure forecloses liability under the misappropriation theory: Because the deception essential to the misappropriation theory involves feigning fidelity to the source of information, if the fiduciary discloses to the source that he plans to trade on the nonpublic information, there is no "deceptive device" and thus no § 10(b) violation—although the fiduciary-turnedtrader may remain liable under state law for breach of a duty of loyalty.^[8]

We turn next to the § 10(b) requirement that the misappropriator's deceptive use of information be "in connection with [656] the purchase or sale of [a] security." This element is satisfied because the fiduciary's fraud is consummated, not when the fiduciary gains the confidential information, but when, without disclosure to his principal, he uses the information to purchase or sell securities. The securities transaction and the breach of duty thus coincide. This is so even though the person or entity defrauded is not the other party to the trade, but is, instead, the source of the nonpublic information. See Aldave, 13 Hofstra L. Rev., at 120 ("a fraud or deceit can be practiced on one person, with resultant harm to another person or group of persons"). A misappropriator who trades on the basis of material, nonpublic information, in short, gains his advantageous market position through deception; he deceives the source of the information and simultaneously harms members of the investing public. See id., at 120-121, and n. 107.

The misappropriation theory targets information of a sort that misappropriators ordinarily capitalize upon to gain norisk profits through the purchase or sale of securities. Should a misappropriator put such information to other use, the statute's prohibition would not be implicated. The theory does not catch all conceivable forms of fraud involving confidential information; rather, it catches fraudulent means of capitalizing on such information through securities transactions.

The Government notes another limitation on the forms of fraud § 10(b) reaches: "The misappropriation theory would not . . . apply to a case in which a person defrauded a bank into giving him a loan or embezzled cash from another, and then used the proceeds of the misdeed to purchase securities." Brief for United States 24, n. 13. In such a case, the Government states, "the proceeds would have value to the malefactor apart from their use in a securities transaction, and the fraud would be complete as soon as the money was obtained." Ibid. In other words, money can buy, if not anything, then at least many things; its misappropriation [657] may thus be viewed as sufficiently detached from a subsequent securities transaction that § 10(b)'s "in connection with" requirement would not be met. Ibid.

Justice Thomas' charge that the misappropriation theory is incoherent because information, like funds, can be put to multiple uses, see post, at 681-686 (opinion concurring in judgment in part and dissenting in part), misses the point. The Exchange Act was enacted in part "to insure the maintenance of fair and honest markets," 15 U. S. C. § 78b, and there is no question that fraudulent uses of confidential information fall within § 10(b)'s prohibition if the fraud is "in connection with" a securities transaction. It is hardly remarkable that a rule suitably applied to the fraudulent uses of certain kinds of information would be stretched beyond reason were it applied to the fraudulent use of money.

Justice Thomas does catch the Government in overstatement. Observing that money can be used for all manner of purposes and purchases, the Government urges that confidential information of the kind at issue derives its value only from its utility in securities trading. See Brief for United States 10, 21; post, at 683-684 (several times emphasizing the word "only"). Substitute "ordinarily" for "only," and the Government is on the mark.^[9]

[658] Our recognition that the Government's "only" is an overstatement has provoked the dissent to cry "new theory." See post, at 687-689. But the very case on which Justice Thomas relies, Motor Vehicle Mfrs. Assn. of United States, Inc. v. State Farm Mut. Automobile Ins. Co., 463 U. S. 29 (1983), shows the extremity of that charge. In State Farm, we reviewed an agency's rescission of a rule under the same "arbitrary and capricious" standard by which the promulgation of a rule under the relevant statute was to be judged, see id., at 41-42; in our decision concluding that the agency had not adequately explained its regulatory action, see id., at 57, we cautioned that a "reviewing court should not attempt itself to make up for such deficiencies," id., at 43. Here, by contrast, Rule 10b—5's promulgation has not been challenged; we consider only the Government's charge that O'Hagan's alleged fraudulent conduct falls within the prohibitions of the Rule and § 10(b). In this context, we acknowledge simply that, in defending the Government's interpretation of the Rule and statute in this Court, the Government's lawyers have pressed a solid point too far, something lawyers, occasionally even judges, are wont to do.

The misappropriation theory comports with § 10(b)'s language, which requires deception "in connection with the purchase or sale of any security," not deception of an identifiable purchaser or seller. The theory is also well tuned to an animating purpose of the Exchange Act: to insure honest securities markets and thereby promote investor confidence. See 45 Fed. Reg. 60412 (1980) (trading on misappropriated information "undermines the integrity of, and investor confidence in, the securities markets"). Although informational disparity is inevitable in the securities markets, investors likely would hesitate to venture their capital in a market where trading based on misappropriated nonpublic information is unchecked by law. An investor's informational disadvantage vis-à-vis a misappropriator with material, nonpublic information [659] stems from contrivance, not luck; it is a disadvantage that cannot be overcome with research or skill. See Brudney, Insiders, Outsiders, and Informational Advantages Under the Federal Securities Laws, 93 Harv. L. Rev. 322, 356 (1979) ("If the market is thought to be systematically populated with . . . transactors [trading on the basis of misappropriated information] some investors will refrain from dealing altogether, and others will incur costs to avoid dealing with such transactors or corruptly to overcome their unerodable informational advantages."); Aldave, 13 Hofstra L. Rev., at 122-123.

In sum, considering the inhibiting impact on market participation of trading on misappropriated information, and the congressional purposes underlying § 10(b), it makes scant sense to hold a lawyer like O'Hagan a § 10(b) violator if he works for a law firm representing the target of a tender offer, but not if he works for a law firm representing the bidder. The text of the statute requires no such result.^[10] The misappropriation at issue here was properly made the subject of a § 10(b) charge because it meets the statutory requirement that there be "deceptive" conduct "in connection with" securities transactions.

[660] C

The Court of Appeals rejected the misappropriation theory primarily on two grounds. First, as the Eighth Circuit comprehended the theory, it requires neither misrepresentation nor nondisclosure. See 92 F. 3d, at 618. As we just explained, however, see supra, at 654-655, deceptive nondisclosure is essential to the § 10(b) liability at issue. Concretely, in this case, "it [was O'Hagan's] failure to disclose his personal trading to Grand Met and Dorsey, in breach of his duty to do so, that ma[de] his conduct `deceptive' within the meaning of [§ ]10(b)." Reply Brief 7.

Second and "more obvious," the Court of Appeals said, the misappropriation theory is not moored to § 10(b)'s requirement that "the fraud be `in connection with the purchase or sale of any security.' " 92 F. 3d, at 618 (quoting 15 U. S. C. § 78j(b)). According to the Eighth Circuit, three of our decisions reveal that § 10(b) liability cannot be predicated on a duty owed to the source of nonpublic information: Chiarella v. United States, 445 U. S. 222 (1980); Dirks v. SEC, 463 U. S. 646 (1983); and Central Bank of Denver, N. A. v. First Interstate Bank of Denver, N. A., 511 U. S. 164 (1994). "[O]nly a breach of a duty to parties to the securities transaction," the Court of Appeals concluded, "or, at the most, to other market participants such as investors, will be sufficient to give rise to § 10(b) liability." 92 F. 3d, at 618. We read the statute and our precedent differently, and note again that § 10(b) refers to "the purchase or sale of any security," not to identifiable purchasers or sellers of securities.

Chiarella involved securities trades by a printer employed at a shop that printed documents announcing corporate takeover bids. See 445 U. S., at 224. Deducing the names of target companies from documents he handled, the printer bought shares of the targets before takeover bids were announced, expecting (correctly) that the share prices would rise upon announcement. In these transactions, the printer did not disclose to the sellers of the securities (the target [661] companies' shareholders) the nonpublic information on which he traded. See ibid. For that trading, the printer was convicted of violating § 10(b) and Rule 10b—5. We reversed the Court of Appeals judgment that had affirmed the conviction. See id., at 225.

The jury in Chiarella had been instructed that it could convict the defendant if he willfully failed to inform sellers of target company securities that he knew of a takeover bid that would increase the value of their shares. See id., at 226. Emphasizing that the printer had no agency or other fiduciary relationship with the sellers, we held that liability could not be imposed on so broad a theory. See id., at 235. There is under § 10(b), we explained, no "general duty between all participants in market transactions to forgo actions based on material, nonpublic information." Id., at 233. Under established doctrine, we said, a duty to disclose or abstain from trading "arises from a specific relationship between two parties." Ibid.

The Court did not hold in Chiarella that the only relationship prompting liability for trading on undisclosed information is the relationship between a corporation's insiders and shareholders. That is evident from our response to the Government's argument before this Court that the printer's misappropriation of information from his employer for purposes of securities trading—in violation of a duty of confidentiality owed to the acquiring companies—constituted fraud in connection with the purchase or sale of a security, and thereby satisfied the terms of § 10(b). Id., at 235-236. The Court declined to reach that potential basis for the printer's liability, because the theory had not been submitted to the jury. See id., at 236-237. But four Justices found merit in it. See id., at 239 (Brennan, J., concurring in judgment); id., at 240-243 (Burger, C. J., dissenting); id., at 245 (Blackmun, J., joined by Marshall, J., dissenting). And a fifth Justice stated that the Court "wisely le[ft] the resolution of this issue for another day." Id., at 238 (Stevens, J., concurring).

[662] Chiarella thus expressly left open the misappropriation theory before us today. Certain statements in Chiarella, however, led the Eighth Circuit in the instant case to conclude that § 10(b) liability hinges exclusively on a breach of duty owed to a purchaser or seller of securities. See 92 F. 3d, at 618. The Court said in Chiarella that § 10(b) liability "is premised upon a duty to disclose arising from a relationship of trust and confidence between parties to a transaction, " 445 U. S., at 230 (emphasis added), and observed that the printshop employee defendant in that case "was not a person in whom the sellers had placed their trust and confidence," see id., at 232. These statements rejected the notion that § 10(b) stretches so far as to impose "a general duty between all participants in market transactions to forgo actions based on material, nonpublic information," id., at 233, and we confine them to that context. The statements highlighted by the Eighth Circuit, in short, appear in an opinion carefully leaving for future resolution the validity of the misappropriation theory, and therefore cannot be read to foreclose that theory.

Dirks, too, left room for application of the misappropriation theory in cases like the one we confront.^[11] Dirks involved an investment analyst who had received information from a former insider of a corporation with which the analyst had no connection. See 463 U. S., at 648-649. The information indicated that the corporation had engaged in a massive fraud. The analyst investigated the fraud, obtaining corroborating information from employees of the corporation. During his investigation, the analyst discussed his findings with clients and investors, some of whom sold their holdings in the company the analyst suspected of gross wrongdoing. See id., at 649.

[663] The SEC censured the analyst for, inter alia, aiding and abetting § 10(b) and Rule 10b—5 violations by clients and investors who sold their holdings based on the nonpublic information the analyst passed on. See id., at 650-652. In the SEC's view, the analyst, as a "tippee" of corporation insiders, had a duty under § 10(b) and Rule 10b—5 to refrain from communicating the nonpublic information to persons likely to trade on the basis of it. See id., at 651, 655-656. This Court found no such obligation, see id., at 665-667, and repeated the key point made in Chiarella: There is no "`general duty between all participants in market transactions to forgo actions based on material, nonpublic information.' " 463 U. S., at 655 (quoting Chiarella, 445 U. S., at 233); see Aldave, 13 Hofstra L. Rev., at 122 (misappropriation theory bars only "trading on the basis of information that the wrongdoer converted to his own use in violation of some fiduciary, contractual, or similar obligation to the owner or rightful possessor of the information").

No showing had been made in Dirks that the "tippers" had violated any duty by disclosing to the analyst nonpublic information about their former employer. The insiders had acted not for personal profit, but to expose a massive fraud within the corporation. See 463 U. S., at 666-667. Absent any violation by the tippers, there could be no derivative liability for the tippee. See id., at 667. Most important for purposes of the instant case, the Court observed in Dirks: "There was no expectation by [the analyst's] sources that he would keep their information in confidence. Nor did [the analyst] misappropriate or illegally obtain the information . . . ." Id., at 665. Dirks thus presents no suggestion that a person who gains nonpublic information through misappropriation in breach of a fiduciary duty escapes § 10(b) liability when, without alerting the source, he trades on the information.

Last of the three cases the Eighth Circuit regarded as warranting disapproval of the misappropriation theory, Cen- [664] tral Bank held that "a private plaintiff may not maintain an aiding and abetting suit under § 10(b)." 511 U. S., at 191. We immediately cautioned in Central Bank that secondary actors in the securities markets may sometimes be chargeable under the securities Acts: "Any person or entity, including a lawyer, accountant, or bank, who employs a manipulative device or makes a material misstatement (or omission) on which a purchaser or seller of securities relies may be liable as a primary violator under 10b—5, assuming . . . the requirements for primary liability under Rule 10b—5 are met." Ibid. (emphasis added). The Eighth Circuit isolated the statement just quoted and drew from it the conclusion that § 10(b) covers only deceptive statements or omissions on which purchasers and sellers, and perhaps other market participants, rely. See 92 F. 3d, at 619. It is evident from the question presented in Central Bank, however, that this Court, in the quoted passage, sought only to clarify that secondary actors, although not subject to aiding and abetting liability, remain subject to primary liability under § 10(b) and Rule 10b—5 for certain conduct.

Furthermore, Central Bank`s discussion concerned only private civil litigation under § 10(b) and Rule 10b—5, not criminal liability. Central Bank`s reference to purchasers or sellers of securities must be read in light of a longstanding limitation on private § 10(b) suits. In Blue Chip Stamps v. Manor Drug Stores, 421 U. S. 723 (1975), we held that only actual purchasers or sellers of securities may maintain a private civil action under § 10(b) and Rule 10b—5. We so confined the § 10(b) private right of action because of "policy considerations." Id., at 737. In particular, Blue Chip Stamps recognized the abuse potential and proof problems inherent in suits by investors who neither bought nor sold, but asserted they would have traded absent fraudulent conduct by others. See id., at 739-747; see also Holmes v. Securities Investor Protection Corporation, 503 U. S. 258, 285 [665] (1992) (O'Connor, J., concurring in part and concurring in judgment); id., at 289-290 (Scalia, J., concurring in judgment). Criminal prosecutions do not present the dangers the Court addressed in Blue Chip Stamps, so that decision is "inapplicable" to indictments for violations of § 10(b) and Rule 10b—5. United States v. Naftalin, 441 U. S. 768, 774, n. 6 (1979); see also Holmes, 503 U. S., at 281 (O'Connor, J., concurring in part and concurring in judgment) ("[T]he purchaser/seller standing requirement for private civil actions under § 10(b) and Rule 10b—5 is of no import in criminal prosecutions for willful violations of those provisions.").

In sum, the misappropriation theory, as we have examined and explained it in this opinion, is both consistent with the statute and with our precedent.^[12] Vital to our decision that criminal liability may be sustained under the misappropriation theory, we emphasize, are two sturdy safeguards Congress has provided regarding scienter. To establish a criminal violation of Rule 10b—5, the Government must prove that a person "willfully" violated the provision. See 15 U. S. C. [666] § 78ff(a).^[13] Furthermore, a defendant may not be imprisoned for violating Rule 10b—5 if he proves that he had no knowledge of the Rule. See ibid.^[14] O'Hagan's charge that the misappropriation theory is too indefinite to permit the imposition of criminal liability, see Brief for Respondent 30— 33, thus fails not only because the theory is limited to those who breach a recognized duty. In addition, the statute's "requirement of the presence of culpable intent as a necessary element of the offense does much to destroy any force in the argument that application of the [statute]" in circumstances such as O'Hagan's is unjust. Boyce Motor Lines, Inc. v. United States, 342 U. S. 337, 342 (1952).

The Eighth Circuit erred in holding that the misappropriation theory is inconsistent with § 10(b). The Court of Appeals may address on remand O'Hagan's other challenges to his convictions under § 10(b) and Rule 10b—5.

III

We consider next the ground on which the Court of Appeals reversed O'Hagan's convictions for fraudulent trading in connection with a tender offer, in violation of § 14(e) of the Exchange Act and SEC Rule 14e—3(a). A sole question is before us as to these convictions: Did the Commission, as the Court of Appeals held, exceed its rulemaking authority under § 14(e) when it adopted Rule 14e—3(a) without requiring a showing that the trading at issue entailed a breach of [667] fiduciary duty? We hold that the Commission, in this regard and to the extent relevant to this case, did not exceed its authority.

The governing statutory provision, § 14(e) of the Exchange Act, reads in relevant part:

"It shall be unlawful for any person . . .to engage in any fraudulent, deceptive, or manipulative acts or practices, in connection with any tender offer . . . . The [SEC] shall, for the purposes of this subsection, by rules and regulations define, and prescribe means reasonably designed to prevent, such acts and practices as are fraudulent, deceptive, or manipulative." 15 U. S. C. § 78n(e).

Section 14(e)'s first sentence prohibits fraudulent acts in connection with a tender offer. This self-operating proscription was one of several provisions added to the Exchange Act in 1968 by the Williams Act, 82 Stat. 454. The section's second sentence delegates definitional and prophylactic rulemaking authority to the Commission. Congress added this rulemaking delegation to § 14(e) in 1970 amendments to the Williams Act. See § 5, 84 Stat. 1497.

Through § 14(e) and other provisions on disclosure in the Williams Act,^[15] Congress sought to ensure that shareholders "confronted by a cash tender offer for their stock [would] not be required to respond without adequate information." Rondeau v. Mosinee Paper Corp. , 422 U. S. 49, 58 (1975); see Lewis v. McGraw, 619 F. 2d 192, 195 (CA2 1980) (per curiam) [668] ("very purpose" of Williams Act was "informed decisionmaking by shareholders"). As we recognized in Schreiber v. Burlington Northern, Inc. , 472 U. S. 1 (1985), Congress designed the Williams Act to make "disclosure, rather than court-imposed principles of `fairness' or `artificiality,' . . . the preferred method of market regulation." Id., at 9, n. 8. Section 14(e), we explained, "supplements the more precise disclosure provisions found elsewhere in the Williams Act, while requiring disclosure more explicitly addressed to the tender offer context than that required by § 10(b)." Id., at 10-11.

Relying on § 14(e)'s rulemaking authorization, the Commission, in 1980, promulgated Rule 14e—3(a). That measure provides:

"(a) If any person has taken a substantial step or steps to commence, or has commenced, a tender offer (the `offering person'), it shall constitute a fraudulent, deceptive or manipulative act or practice within the meaning of section 14(e) of the [Exchange] Act for any other person who is in possession of material information relating to such tender offer which information he knows or has reason to know is nonpublic and which he knows or has reason to know has been acquired directly or indirectly from:

"(1) The offering person,

"(2) The issuer of the securities sought or to be sought by such tender offer, or

"(3) Any officer, director, partner or employee or any other person acting on behalf of the offering person or such issuer, to purchase or sell or cause to be purchased or sold any of such securities or any securities convertible into or exchangeable for any such securities or any option or right to obtain or to dispose of any of the foregoing securities, unless within a reasonable time prior to any purchase or sale such information and its source [669] are publicly disclosed by press release or otherwise." 17 CFR § 240.14e—3(a) (1996).

As characterized by the Commission, Rule 14e—3(a) is a "disclose or abstain from trading" requirement. 45 Fed. Reg. 60410 (1980).^[16] The Second Circuit concisely described the Rule's thrust:

"One violates Rule 14e—3(a) if he trades on the basis of material nonpublic information concerning a pending tender offer that he knows or has reason to know has been acquired `directly or indirectly' from an insider of the offer or or issuer, or someone working on their behalf. Rule 14e—3(a) is a disclosure provision. It creates a duty in those traders who fall within its ambit to abstain or disclose, without regard to whether the trader owes a pre-existing fiduciary duty to respect the confidentiality of the information." United States v. Chestman, 947 F. 2d 551, 557 (1991) (en banc) (emphasis added), cert. denied, 503 U. S. 1004 (1992).

See also SEC v. Maio, 51 F. 3d 623, 635 (CA7 1995) ("Rule 14e—3 creates a duty to disclose material non-public information, or abstain from trading in stocks implicated by an impending tender offer, regardless of whether such information was obtained through a breach of fiduciary duty." (emphasis added)); SEC v. Peters, 978 F. 2d 1162, 1165 (CA10 1992) (as written, Rule 14e—3(a) has no fiduciary duty requirement).

In the Eighth Circuit's view, because Rule 14e—3(a) applies whether or not the trading in question breaches a fiduciary duty, the regulation exceeds the SEC's § 14(e) rulemaking authority. See 92 F. 3d, at 624, 627. Contra, Maio, 51 F. 3d, at 634-635 (CA7); Peters, 978 F. 2d, at 1165-1167 (CA10); [670] Chestman, 947 F. 2d, at 556-563 (CA2) (all holding Rule 14e— 3(a) a proper exercise of SEC's statutory authority). In support of its holding, the Eighth Circuit relied on the text of § 14(e) and our decisions in Schreiber and Chiarella. See 92 F. 3d, at 624-627.

The Eighth Circuit homed in on the essence of § 14(e)'s rulemaking authorization: "[T]he statute empowers the SEC to `define' and `prescribe means reasonably designed to prevent' `acts and practices' which are `fraudulent.' " Id., at 624. All that means, the Eighth Circuit found plain, is that the SEC may "identify and regulate," in the tender offer context, "acts and practices" the law already defines as "fraudulent"; but, the Eighth Circuit maintained, the SEC may not "create its own definition of fraud." Ibid. (internal quotation marks omitted).

This Court, the Eighth Circuit pointed out, held in Schreiber that the word "manipulative" in the § 14(e) phrase "fraudulent, deceptive, or manipulative acts or practices" means just what the word means in § 10(b): Absent misrepresentation or nondisclosure, an act cannot be indicted as manipulative. See 92 F. 3d, at 625 (citing Schreiber, 472 U. S., at 7-8, and n. 6). Section 10(b) interpretations guide construction of § 14(e), the Eighth Circuit added, see 92 F. 3d, at 625, citing this Court's acknowledgment in Schreiber that § 14(e)'s "`broad antifraud prohibition' . . . [is] modeled on the antifraud provisions of § 10(b) . . . and Rule 10b—5," 472 U. S., at 10 (citation omitted); see id., at 10-11, n. 10.

For the meaning of "fraudulent" under § 10(b), the Eighth Circuit looked to Chiarella. See 92 F. 3d, at 625. In that case, the Eighth Circuit recounted, this Court held that a failure to disclose information could be "fraudulent" under § 10(b) only when there was a duty to speak arising out of "`a fiduciary or other similar relation of trust and confidence.' " Chiarella, 445 U. S., at 228 (quoting Restatement (Second) of Torts § 551(2)(a) (1976)). Just as § 10(b) demands a showing [671] of a breach of fiduciary duty, so such a breach is necessary to make out a § 14(e) violation, the Eighth Circuit concluded.

As to the Commission's § 14(e) authority to "prescribe means reasonably designed to prevent" fraudulent acts, the Eighth Circuit stated: "Properly read, this provision means simply that the SEC has broad regulatory powers in the field of tender offers, but the statutory terms have a fixed meaning which the SEC cannot alter by way of an administrative rule." 92 F. 3d, at 627.

The United States urges that the Eighth Circuit's reading of § 14(e) misapprehends both the Commission's authority to define fraudulent acts and the Commission's power to prevent them. "The `defining' power," the United States submits, "would be a virtual nullity were the SEC not permitted to go beyond common law fraud (which is separately prohibited in the first [self-operative] sentence of Section 14(e))." Brief for United States 11; see id., at 37.

In maintaining that the Commission's power to define fraudulent acts under § 14(e) is broader than its rulemaking power under § 10(b), the United States questions the Court of Appeals' reading of Schreiber. See Brief for United States 38-40. Parenthetically, the United States notes that the word before the Schreiber Court was "manipulative"; unlike "fraudulent," the United States observes, "`manipulative' . . . is `virtually a term of art when used in connection with the securities markets.' " Brief for United States 38, n. 20 (quoting Schreiber, 472 U. S., at 6). Most tellingly, the United States submits, Schreiber involved acts alleged to violate the self-operative provision in § 14(e)'s first sentence, a sentence containing language similar to § 10(b). But § 14(e)'s second sentence, containing the rulemaking authorization, the United States points out, does not track § 10(b), which simply authorizes the SEC to proscribe "manipulative or deceptive device[s] or contrivance[s]." Brief for United States 38. Instead, § 14(e)'s rulemaking prescription tracks § 15(c)(2)(D) of the Exchange Act, 15 U. S. C. § 78o (c)(2)(D), [672] which concerns the conduct of broker-dealers in over-thecounter markets. See Brief for United States 38-39. Since 1938, see 52 Stat. 1075, § 15(c)(2) has given the Commission authority to "define, and prescribe means reasonably designed to prevent, such [broker-dealer] acts and practices as are fraudulent, deceptive, or manipulative." 15 U. S. C. § 78o (c)(2)(D). When Congress added this same rulemaking language to § 14(e) in 1970, the Government states, the Commission had already used its § 15(c)(2) authority to reach beyond common-law fraud. See Brief for United States 39, n. 22.^[17]

We need not resolve in this case whether the Commission's authority under § 14(e) to "define . . . such acts and practices as are fraudulent" is broader than the Commission's frauddefining authority under § 10(b), for we agree with the United States that Rule 14e—3(a), as applied to cases of this genre, qualifies under § 14(e) as a "means reasonably designed to prevent" fraudulent trading on material, nonpublic information in the tender offer context.^[18] A prophylactic [673] measure, because its mission is to prevent, typically encompasses more than the core activity prohibited. As we noted in Schreiber, § 14(e)'s rulemaking authorization gives the Commission "latitude," even in the context of a term of art like "manipulative," "to regulate nondeceptive activities as a `reasonably designed' means of preventing manipulative acts, without suggesting any change in the meaning of the term `manipulative' itself." 472 U. S., at 11, n. 11. We hold, accordingly, that under § 14(e), the Commission may prohibit acts not themselves fraudulent under the common law or § 10(b), if the prohibition is "reasonably designed to prevent. . . acts and practices [that] are fraudulent." 15 U. S. C. § 78n(e).^[19]

Because Congress has authorized the Commission, in § 14(e), to prescribe legislative rules, we owe the Commission's judgment "more than mere deference or weight." Batterton v. Francis, 432 U. S. 416, 424-426 (1977). Therefore, in determining whether Rule 14e—3(a)'s "disclose or abstain from trading" requirement is reasonably designed to prevent fraudulent acts, we must accord the Commission's assessment "controlling weight unless [it is] arbitrary, capricious, or manifestly contrary to the statute." Chevron U. S. A. Inc. v. Natural Resources Defense Council, Inc. , 467 U. S. 837, 844 (1984). In this case, we conclude, the Commission's assessment is none of these.^[20]

[674] In adopting the "disclose or abstain" rule, the SEC explained:

"The Commission has previously expressed and continues to have serious concerns about trading by persons in possession of material, nonpublic information relating to a tender offer. This practice results in unfair disparities in market information and market disruption. Security holders who purchase from or sell to such persons are effectively denied the benefits of disclosure and the substantive protections of the Williams Act. If furnished with the information, these security holders would be able to make an informed investment decision, which could involve deferring the purchase or sale of the securities until the material information had been disseminated or until the tender offer had been commenced or terminated." 45 Fed. Reg. 60412 (1980) (footnotes omitted).

The Commission thus justified Rule 14e—3(a) as a means necessary and proper to assure the efficacy of Williams Act protections.

The United States emphasizes that Rule 14e—3(a) reaches trading in which "a breach of duty is likely but difficult to prove." Reply Brief 16. "Particularly in the context of a tender offer," as the Tenth Circuit recognized, "there is a fairly wide circle of people with confidential information," Peters, 978 F. 2d, at 1167, notably, the attorneys, investment [675] bankers, and accountants involved in structuring the transaction. The availability of that information may lead to abuse, for "even a hint of an upcoming tender offer may send the price of the target company's stock soaring." SEC v. Materia, 745 F. 2d 197, 199 (CA2 1984). Individuals entrusted with nonpublic information, particularly if they have no long-term loyalty to the issuer, may find the temptation to trade on that information hard to resist in view of "the very large short-term profits potentially available [to them]." Peters, 978 F. 2d, at 1167.

"[I]t may be possible to prove circumstantially that a person [traded on the basis of material, nonpublic information], but almost impossible to prove that the trader obtained such information in breach of a fiduciary duty owed either by the trader or by the ultimate insider source of the information." Ibid. The example of a "tippee" who trades on information received from an insider illustrates the problem. Under Rule 10b—5, "a tippee assumes a fiduciary duty to the shareholders of a corporation not to trade on material nonpublic information only when the insider has breached his fiduciary duty to the shareholders by disclosing the information to the tippee and the tippee knows or should know that there has been a breach." Dirks , 463 U. S., at 660. To show that a tippee who traded on nonpublic information about a tender offer had breached a fiduciary duty would require proof not only that the insider source breached a fiduciary duty, but that the tippee knew or should have known of that breach. "Yet, in most cases, the only parties to the [information transfer] will be the insider and the alleged tippee." Peters, 978 F. 2d, at 1167.^[21]

[676] In sum, it is a fair assumption that trading on the basis of material, nonpublic information will often involve a breach of a duty of confidentiality to the bidder or target company or their representatives. The SEC, cognizant of the proof problem that could enable sophisticated traders to escape responsibility, placed in Rule 14e—3(a) a "disclose or abstain from trading" command that does not require specific proof of a breach of fiduciary duty. That prescription, we are satisfied, applied to this case, is a "means reasonably designed to prevent" fraudulent trading on material, nonpublic information in the tender offer context. See Chestman, 947 F. 2d, at 560 ("While dispensing with the subtle problems of proof associated with demonstrating fiduciary breach in the problematic area of tender offer insider trading, [Rule 14e— 3(a)] retains a close nexus between the prohibited conduct and the statutory aims."); accord, Maio, 51 F. 3d, at 635, and n. 14; Peters, 978 F. 2d, at 1167.^[22] Therefore, insofar as it serves to prevent the type of misappropriation charged against O'Hagan, Rule 14e—3(a) is a proper exercise of the Commission's prophylactic power under § 14(e).^[23]

As an alternate ground for affirming the Eighth Circuit's judgment, O'Hagan urges that Rule 14e—3(a) is invalid because [677] it prohibits trading in advance of a tender offer—when "a substantial step . . . to commence" such an offer has been taken—while § 14(e) prohibits fraudulent acts "in connection with any tender offer." See Brief for Respondent 41-42. O'Hagan further contends that, by covering pre-offer conduct, Rule 14e—3(a) "fails to comport with due process on two levels": The Rule does not "give fair notice as to when, in advance of a tender offer, a violation of § 14(e) occurs," id., at 42; and it"disposes of any scienter requirement," id., at 43. The Court of Appeals did not address these arguments, and O'Hagan did not raise the due process points in his briefs before that court. We decline to consider these contentions in the first instance.^[24] The Court of Appeals may address on remand any arguments O'Hagan has preserved.

IV

Based on its dispositions of the securities fraud convictions, the Court of Appeals also reversed O'Hagan's convictions, under 18 U. S. C. § 1341, for mail fraud. See 92 F. 3d, at 627-628. Reversal of the securities convictions, the Court of Appeals recognized, "d[id] not as a matter of law require that the mail fraud convictions likewise be reversed." Id., at 627 (citing Carpenter, 484 U. S., at 24, in which this Court unanimously affirmed mail and wire fraud convictions based on the same conduct that evenly divided the Court on the defendants' securities fraud convictions). But in this case, the Court of Appeals said, the indictment was so structured that the mail fraud charges could not be disassociated from the securities fraud charges, and absent any securities [678] fraud, "there was no fraud upon which to base the mail fraud charges." 92 F. 3d, at 627-628.^[25]

The United States urges that the Court of Appeals' position is irreconcilable with Carpenter: Just as in Carpenter, so here, the "mail fraud charges are independent of [the] securities fraud charges, even [though] both rest on the same set of facts." Brief for United States 46-47. We need not linger over this matter, for our rulings on the securities fraud issues require that we reverse the Court of Appeals judgment on the mail fraud counts as well.^[26]

O'Hagan, we note, attacked the mail fraud convictions in the Court of Appeals on alternate grounds; his other arguments, not yet addressed by the Eighth Circuit, remain open for consideration on remand.

* * *

The judgment of the Court of Appeals for the Eighth Circuit is reversed, and the case is remanded for further proceedings consistent with this opinion.

It is so ordered.

[679] Justice Scalia, concurring in part and dissenting in part.

I join Parts I, III, and IV of the Court's opinion. I do not agree, however, with Part II of the Court's opinion, containing its analysis of respondent's convictions under § 10(b) and Rule 10b—5.

I do not entirely agree with Justice Thomas's analysis of those convictions either, principally because it seems to me irrelevant whether the Government's theory of why respondent's acts were covered is "coherent and consistent," post, at 691. It is true that with respect to matters over which an agency has been accorded adjudicative authority or policymaking discretion, the agency's action must be supported by the reasons that the agency sets forth, SEC v. Chenery Corp., 318 U. S. 80, 94 (1943); see also SEC v. Chenery Corp., 332 U. S. 194, 196 (1947), but I do not think an agency's unadorned application of the law need be, at least where (as here) no Chevron deference is being given to the agency's interpretation, see Chevron U. S. A. Inc. v. Natural Resources Defense Council, Inc., 467 U. S. 837 (1984). In point of fact, respondent's actions either violated § 10(b) and Rule 10b—5, or they did not—regardless of the reasons the Government gave. And it is for us to decide.

While the Court's explanation of the scope of § 10(b) and Rule 10b—5 would be entirely reasonable in some other context, it does not seem to accord with the principle of lenity we apply to criminal statutes (which cannot be mitigated here by the Rule, which is no less ambiguous than the statute). See Reno v. Koray, 515 U. S. 50, 64-65 (1995) (explaining circumstances in which rule of levity applies); United States v. Bass, 404 U. S. 336, 347-348 (1971) (discussing policies underlying rule of lenity). In light of that principle, it seems to me that the unelaborated statutory language: "[t]o use or employ, in connection with the purchase or sale of any security . . . any manipulative or deceptive device or contrivance," § 10(b), must be construed to require the manipulation or deception of a party to a securities transaction.

[680] Justice Thomas, with whom The Chief Justice joins, concurring in the judgment in part and dissenting in part.

Today the majority upholds respondent's convictions for violating § 10(b) of the Securities Exchange Act of 1934, and Rule 10b—5 promulgated thereunder, based upon the Securities and Exchange Commission's "misappropriation theory." Central to the majority's holding is the need to interpret § 10(b)'s requirement that a deceptive device be "use[d] or employ[ed], in connection with the purchase or sale of any security." 15 U. S. C. § 78j(b). Because the Commission's misappropriation theory fails to provide a coherent and consistent interpretation of this essential requirement for liability under § 10(b), I dissent.

The majority also sustains respondent's convictions under § 14(e) of the Securities Exchange Act, and Rule 14e—3(a) promulgated thereunder, regardless of whether respondent violated a fiduciary duty to anybody. I dissent too from that holding because, while § 14(e) does allow regulations prohibiting nonfraudulent acts as a prophylactic against certain fraudulent acts, neither the majority nor the Commission identifies any relevant underlying fraud against which Rule 14e—3(a) reasonably provides prophylaxis. With regard to respondent's mail fraud convictions, however, I concur in the judgment of the Court.

I

I do not take issue with the majority's determination that the undisclosed misappropriation of confidential information by a fiduciary can constitute a "deceptive device" within the meaning of § 10(b). Nondisclosure where there is a preexisting duty to disclose satisfies our definitions of fraud and deceit for purposes of the securities laws. See Chiarella v. United States, 445 U. S. 222, 230 (1980).

Unlike the majority, however, I cannot accept the Commission's interpretation of when a deceptive device is "use[d] . . . in connection with" a securities transaction. Although the Commission and the majority at points seem to suggest that [681] any relation to a securities transaction satisfies the "in connection with" requirement of § 10(b), both ultimately reject such an overly expansive construction and require a more integral connection between the fraud and the securities transaction. The majority states, for example, that the misappropriation theory applies to undisclosed misappropriation of confidential information "for securities trading purposes," ante, at 652, thus seeming to require a particular intent by the misappropriator in order to satisfy the "in connection with" language. See also ante, at 656 (the "misappropriation theory targets information of a sort that misappropriators ordinarily capitalize upon to gain no-risk profits through the purchase or sale of securities" (emphasis added)); ante, at 656-657 (distinguishing embezzlement of money used to buy securities as lacking the requisite connection). The Commission goes further, and argues that the misappropriation theory satisfies the "in connection with" requirement because it "depends on an inherent connection between the deceptive conduct and the purchase or sale of a security." Brief for United States 21 (emphasis added); see also ibid. (the "misappropriated information had personal value to respondent only because of its utility in securities trading" (emphasis added)).

The Commission's construction of the relevant language in § 10(b), and the incoherence of that construction, become evident as the majority attempts to describe why the fraudulent theft of information falls under the Commission's misappropriation theory, but the fraudulent theft of money does not. The majority correctly notes that confidential information "qualifies as property to which the company has a right of exclusive use." Ante, at 654. It then observes that the "undisclosed misappropriation of such information, in violation of a fiduciary duty, . . . constitutes fraud akin to embezzlement—the fraudulent appropriation to one's own use of the money or goods entrusted to one's care by another." [682] Ibid. (citations and internal quotation marks omitted).^[27] So far the majority's analogy to embezzlement is well taken, and adequately demonstrates that undisclosed misappropriation can be a fraud on the source of the information.

What the embezzlement analogy does not do, however, is explain how the relevant fraud is "use[d] or employ[ed], in connection with" a securities transaction. And when the majority seeks to distinguish the embezzlement of funds from the embezzlement of information, it becomes clear that neither the Commission nor the majority has a coherent theory regarding § 10(b)'s "in connection with" requirement.

Turning first to why embezzlement of information supposedly meets the "in connection with" requirement, the majority asserts that the requirement

"is satisfied because the fiduciary's fraud is consummated, not when the fiduciary gains the confidential information, but when, without disclosure to his principal, he uses the information to purchase or sell securities. The securities transaction and the breach of duty thus coincide." Ante, at 656.

The majority later notes, with apparent approval, the Government's contention that the embezzlement of funds used to purchase securities would not fall within the misappropriation theory. Ante, at 656-657 (citing Brief for United States 24, n. 13). The misappropriation of funds used for a securities transaction is not covered by its theory, the Government explains, because "the proceeds would have value to the malefactor apart from their use in a securities transaction, and the fraud would be complete as soon as the money was [683] obtained." Brief for United States 24, n. 13; see ante, at 656 (quoting Government's explanation).

Accepting the Government's description of the scope of its own theory, it becomes plain that the majority's explanation of how the misappropriation theory supposedly satisfies the "in connection with" requirement is incomplete. The touchstone required for an embezzlement to be "use[d] or employ[ed], in connection with" a securities transaction is not merely that it "coincide" with, or be consummated by, the transaction, but that it is necessarily and only consummated by the transaction. Where the property being embezzled has value "apart from [its] use in a securities transaction"— even though it is in fact being used in a securities transaction—the Government contends that there is no violation under the misappropriation theory.

My understanding of the Government's proffered theory of liability, and its construction of the "in connection with" requirement, is confirmed by the Government's explanation during oral argument:

"[Court]: What if I appropriate some of my client's money in order to buy stock?

. . . . .

"[Court]: Have I violated the securities laws?

"[Counsel]: I do not think that you have.

"[Court]: Why not? Isn't that in connection with the purchase of securit[ies] just as much as this one is?

"[Counsel]: It's not just as much as this one is, because in this case it is the use of the information that enables the profits, pure and simple. There would be no opportunity to engage in profit—

"[Court]: Same here. I didn't have the money. The only way I could buy this stock was to get the money.

. . . . .

"[Counsel]: The difference . . . is that once you have the money you can do anything you want with it. In a sense, the fraud is complete at that point, and then you [684] go on and you can use the money to finance any number of other activities, but the connection is far less close than in this case, where the only value of this informa- tion for personal profit for respondent was to take it and profit in the securities markets by trading on it.

. . . . .

"[Court]: So what you're saying is, is in this case the misappropriation can only be of relevance, or is of substantial relevance, is with reference to the purchase of securities.

"[Counsel]: Exactly.

"[Court]: When you take the money out of the accounts you can go to the racetrack, or whatever.

"[Counsel]: That's exactly right, and because of that difference, [there] can be no doubt that this kind of misappropriation of property is in connection with the purchase or sale of securities.

"Other kinds of misappropriation of property may or may not, but this is a unique form of fraud, unique to the securities markets, in fact, because the only way in which respondent could have profited through this in- formation is by either trading on it or by tipping somebody else to enable their trades." Tr. of Oral Arg. 16-19 (emphases added).

As the above exchange demonstrates, the relevant distinction is not that the misappropriated information was used for a securities transaction (the money example met that test), but rather that it could only be used for such a transaction. See also id., at 6-7 (Government contention that the misappropriation theory satisfies "the requisite connection between the fraud and the securities trading, because it is only in the trading that the fraud is consummated" (emphasis added)); id., at 8 (same).

The Government's construction of the "in connection with" requirement—and its claim that such requirement precludes coverage of financial embezzlement—also demonstrates how [685] the majority's described distinction of financial embezzlement is incomplete. Although the majority claims that the fraud in a financial embezzlement case is complete as soon as the money is obtained, and before the securities transaction is consummated, that is not uniformly true, and thus cannot be the Government's basis for claiming that such embezzlement does not violate the securities laws. It is not difficult to imagine an embezzlement of money that takes place via the mechanism of a securities transaction—for example where a broker is directed to purchase stock for a client and instead purchases such stock—using client funds—for his own account. The unauthorized (and presumably undisclosed) transaction is the very act that constitutes the embezzlement and the "securities transaction and the breach of duty thus coincide." What presumably distinguishes monetary embezzlement for the Government is thus that it is not necessarily coincident with a securities transaction, not that it never lacks such a "connection."

Once the Government's construction of the misappropriation theory is accurately described and accepted—along with its implied construction of § 10(b)'s "in connection with" language—that theory should no longer cover cases, such as this one, involving fraud on the source of information where the source has no connection with the other participant in a securities transaction. It seems obvious that the undisclosed misappropriation of confidential information is not necessarily consummated by a securities transaction. In this case, for example, upon learning of Grand Met's confidential takeover plans, O'Hagan could have done any number of things with the information: He could have sold it to a newspaper for publication, see id., at 36; he could have given or sold the information to Pillsbury itself, see id., at 37; or he could even have kept the information and used it solely for his personal amusement, perhaps in a fantasy stock trading game.

Any of these activities would have deprived Grand Met of its right to "exclusive use," ante, at 654, of the information [686] and, if undisclosed, would constitute "embezzlement" of Grand Met's informational property. Under any theory of liability, however, these activities would not violate § 10(b) and, according to the Commission's monetary embezzlement analogy, these possibilities are sufficient to preclude a violation under the misappropriation theory even where the informational property was used for securities trading. That O'Hagan actually did use the information to purchase securities is thus no more significant here than it is in the case of embezzling money used to purchase securities. In both cases the embezzler could have done something else with the property, and hence the Commission's necessary "connection" under the securities laws would not be met.^[28] If the relevant test under the "in connection with" language is whether the fraudulent act is necessarily tied to a securities transaction, then the misappropriation of confidential information used to trade no more violates § 10(b) than does the misappropriation of funds used to trade. As the Commission concedes that the latter is not covered under its theory, I am at a loss to see how the same theory can coherently be applied to the former.^[29]

[687] The majority makes no attempt to defend the misappropriation theory as set forth by the Commission. Indeed, the majority implicitly concedes the indefensibility of the Commission's theory by acknowledging that alternative uses of misappropriated information exist that do not violate the securities laws and then dismissing the Government's repeated explanations of its misappropriation theory as mere "overstatement." Ante, at 657. Having rejected the Government's description of its theory, the majority then engages in the "imaginative" exercise of constructing its own misappropriation theory from whole cloth. Thus, we are told, if we merely "[s]ubstitute `ordinarily' for `only' " when describing the degree of connecteness between a misappropriation and a securities transaction, the Government would have a winner. Ibid. Presumably, the majority would similarly edit the Government's brief to this Court to argue for only an "ordinary," rather than an "inherent connection between the deceptive conduct and the purchase or sale of a security." Brief for United States 21 (emphasis added).

I need not address the coherence, or lack thereof, of the majority's new theory, for it suffers from a far greater, and dispositive, flaw: It is not the theory offered by the Commission. Indeed, as far as we know from the majority's opinion, this new theory has never been proposed by the Commission, much less adopted by rule or otherwise. It is a fundamental proposition of law that this Court "may not supply a reasoned basis for the agency's action that the agency itself has not given." Motor Vehicle Mfrs. Assn. of United States, Inc. v. State Farm Mut. Automobile Ins. Co., 463 U. S. 29, 43 (1983). We do not even credit a "post hoc rationalizatio[n]" of counsel for the agency, id., at 50, so one is left to wonder how we could possibly rely on a post hoc rationalization [688] invented by this Court and never even presented by the Commission for our consideration.

Whether the majority's new theory has merit, we cannot possibly tell on the record before us. There are no findings regarding the "ordinary" use of misappropriated information, much less regarding the "ordinary" use of other forms of embezzled property. The Commission has not opined on the scope of the new requirement that property must "ordinarily" be used for securities trading in order for its misappropriation to be "in connection with" a securities transaction. We simply do not know what would or would not be covered by such a requirement, and hence cannot evaluate whether the requirement embodies a consistent and coherent interpretation of the statute.^[30] Moreover, persons subject to [689] this new theory, such as respondent here, surely could not and cannot regulate their behavior to comply with the new theory because, until today, the theory has never existed. In short, the majority's new theory is simply not presented by this case, and cannot form the basis for upholding respondent's convictions.

In upholding respondent's convictions under the new and improved misappropriation theory, the majority also points to various policy considerations underlying the securities laws, such as maintaining fair and honest markets, promoting investor confidence, and protecting the integrity of the securities markets. Ante, at 657, 658-659. But the repeated reliance on such broad-sweeping legislative purposes reaches too far and is misleading in the context of the misappropriation theory. It reaches too far in that, regardless of the overarching purpose of the securities laws, it is not illegal to run afoul of the "purpose" of a statute, only its letter. The majority's approach is misleading in this case because it glosses over the fact that the supposed threat to fair and honest markets, investor confidence, and market integrity comes not from the supposed fraud in this case, but from the mere fact that the information used by O'Hagan was nonpublic.

As the majority concedes, because "the deception essential to the misappropriation theory involves feigning fidelity to the source of information, if the fiduciary discloses to the source that he plans to trade on the nonpublic information, there is no `deceptive device' and thus no § 10(b) violation." Ante, at 655 (emphasis added). Indeed, were the source expressly to authorize its agents to trade on the confidential information—as a perk or bonus, perhaps—there would likewise be no § 10(b) violation.^[31] Yet in either case—disclosed [690] misuse or authorized use—the hypothesized "inhibiting impact on market participation," ante, at 659, would be identical to that from behavior violating the misappropriation theory: "Outsiders" would still be trading based on nonpublic information that the average investor has no hope of obtaining through his own diligence.^[32]

The majority's statement that a "misappropriator who trades on the basis of material, nonpublic information, in short, gains his advantageous market position through deception; he deceives the source of the information and simultaneously harms members of the investing public, " ante, at 656 (emphasis added), thus focuses on the wrong point. Even if it is true that trading on nonpublic information hurts the public, it is true whether or not there is any deception of the source of the information.^[33] Moreover, as [691] we have repeatedly held, use of nonpublic information to trade is not itself a violation of § 10(b). E. g., Chiarella, 445 U. S., at 232-233. Rather, it is the use of fraud "in connection with" a securities transaction that is forbidden. Where the relevant element of fraud has no impact on the integrity of the subsequent transactions as distinct from the nonfraudulent element of using nonpublic information, one can reasonably question whether the fraud was used in connection with a securities transaction. And one can likewise question whether removing that aspect of fraud, though perhaps laudable, has anything to do with the confidence or integrity of the market.

The absence of a coherent and consistent misappropriation theory and, by necessary implication, a coherent and consistent application of the statutory "use or employ, in connection with" language, is particularly problematic in the context of this case. The Government claims a remarkable breadth to the delegation of authority in § 10(b), arguing that "the very aim of this section was to pick up unforeseen, cunning, deceptive devices that people might cleverly use in the securities markets." Tr. of Oral Arg. 7. As the Court aptly queried, "[t]hat's rather unusual, for a criminal statute to be that open-ended, isn't it?" Ibid. Unusual indeed. Putting aside the dubious validity of an open-ended delegation to an independent agency to go forth and create regulations criminalizing "fraud," in this case we do not even have a formal regulation embodying the agency's misappropriation theory. Certainly Rule 10b—5 cannot be said to embody the theory— although it deviates from the statutory language by the addition of the words "any person," it merely repeats, unchanged, § 10(b)'s "in connection with" language. Given that the validity of the misappropriation theory turns on the construction [692] of that language in § 10(b), the regulatory language is singularly uninformative.^[34]

Because we have no regulation squarely setting forth some version of the misappropriation theory as the Commission's interpretation of the statutory language, we are left with little more than the Commission's litigating position or the majority's completely novel theory that is not even acknowledged, much less adopted, by the Commission. As we have noted before, such positions are not entitled to deference and, at most, get such weight as their persuasiveness warrants. Metropolitan Stevedore Co. v. Rambo, ante, at 138, n. 9, 140, n. 10. Yet I find wholly unpersuasive a litigating position by the Commission that, at best, embodies an inconsistent and incoherent interpretation of the relevant statutory language and that does not provide any predictable guidance as to what behavior contravenes the statute. That position is no better than an ad hoc interpretation of statutory language and in my view can provide no basis for liability.

II

I am also of the view that O'Hagan's conviction for violating Rule 14e—3(a) cannot stand. Section 14(e) of the Exchange Act provides, in relevant part:

"It shall be unlawful for any person . . . to engage in any fraudulent, deceptive, or manipulative acts or practices, in connection with any tender offer . . . . The Commission shall, for the purposes of this subsection, by rules and regulations define, and prescribe means [693] reasonably designed to prevent, such acts and practices as are fraudulent, deceptive, or manipulative." 15 U. S. C. § 78n(e).

Pursuant to the rulemaking authority conferred by this section, the Commission has promulgated Rule 14e—3(a), which provides, in relevant part:

"(a) If any person has taken a substantial step or steps to commence, or has commenced, a tender offer (the `offering person'), it shall constitute a fraudulent, deceptive or manipulative act or practice within the meaning of section 14(e) of the [Securities Exchange] Act for any other person who is in possession of material information relating to such tender offer which information he knows or has reason to know is nonpublic and which he knows or has reason to know has been acquired directly or indirectly from:

"(1) The offering person,

"(2) The issuer of the securities sought or to be sought by such tender offer, or

"(3) [Any person acting on behalf of the offering person or such issuer], to purchase or sell [any such securities or various instruments related to such securities], unless within a reasonable time prior to any purchase or sale such information and its source are publicly disclosed by press release or otherwise." 17 CFR § 240.14e—3(a) (1996).

As the majority acknowledges, Rule 14e—3(a) prohibits a broad range of behavior regardless of whether such behavior is fraudulent under our precedents. See ante, at 669 (Rule applies "`without regard to whether the trader owes a preexisting fiduciary duty to respect the confidentiality of the information' " (emphasis deleted)) (quoting United States v. Chestman, 947 F. 2d 551, 557 (CA2 1991) (en banc), cert. denied, 503 U. S. 1004 (1992)).

[694] The Commission offers two grounds in defense of Rule 14e—3(a). First, it argues that § 14(e) delegates to the Commission the authority to "define" fraud differently than that concept has been defined by this Court, and that Rule 14e— 3(a) is a valid exercise of that "defining" power. Second, it argues that § 14(e) authorizes the Commission to "prescribe means reasonably designed to prevent" fraudulent acts, and that Rule 14e—3(a) is a prophylactic rule that may prohibit nonfraudulent acts as a means of preventing fraudulent acts that are difficult to detect or prove.

The majority declines to reach the Commission's first justification, instead sustaining Rule 14e—3(a) on the ground that

"under § 14(e), the Commission may prohibit acts not themselves fraudulent under the common law or § 10(b), if the prohibition is `reasonably designed to prevent . . . acts and practices [that] are fraudulent.' " Ante, at 673 (quoting 15 U. S. C. § 78n(e)).

According to the majority, prohibiting trading on nonpublic information is necessary to prevent such supposedly hardto-prove fraudulent acts and practices as trading on information obtained from the buyer in breach of a fiduciary duty, ante, at 675, and possibly "warehousing," whereby the buyer tips allies prior to announcing the tender offer and encourages them to purchase the target company's stock, ante, at 672-673, n. 17.^[35]

I find neither of the Commission's justifications for Rule 14e—3(a) acceptable in misappropriation cases. With regard to the Commission's claim of authority to redefine the concept of fraud, I agree with the Eighth Circuit that the Commission misreads the relevant provision of § 14(e).

[695] "Simply put, the enabling provision of § 14(e) permits the SEC to identify and regulate those `acts and practices' which fall within the § 14(e) legal definition of `fraudulent,' but it does not grant the SEC a license to redefine the term." 92 F. 3d 612, 624 (1996).

This conclusion follows easily from our similar statement in Schreiber v. Burlington Northern, Inc., 472 U. S. 1, 11, n. 11 (1985), that § 14(e) gives the "Commission latitude to regulate nondeceptive activities as a `reasonably designed' means of preventing manipulative acts, without suggesting any change in the meaning of the term `manipulative' itself."

Insofar as the Rule 14e—3(a) purports to "define" acts and practices that "are fraudulent," it must be measured against our precedents interpreting the scope of fraud. The majority concedes, however, that Rule 14e—3(a) does not prohibit merely trading in connection with fraudulent nondisclosure, but rather it prohibits trading in connection with any nondisclosure, regardless of the presence of a pre-existing duty to disclose. Ante, at 669. The Rule thus exceeds the scope of the Commission's authority to define such acts and practices as "are fraudulent."^[36]

[696] Turning to the Commission's second justification for Rule 14e—3(a), although I can agree with the majority that § 14(e) authorizes the Commission to prohibit nonfraudulent acts as a means reasonably designed to prevent fraudulent ones, I cannot agree that Rule 14e—3(a) satisfies this standard. As an initial matter, the Rule, on its face, does not purport to be an exercise of the Commission's prophylactic power, but rather a redefinition of what "constitute[s] a fraudulent, deceptive, or manipulative act or practice within the meaning of § 14(e)." That Rule 14e—3(a) could have been "conceived and defended, alternatively, as definitional or preventive," ante, at 674, n. 19, misses the point. We evaluate regulations not based on the myriad of explanations that could have been given by the relevant agency, but on those explanations and justifications that were, in fact, given. See State Farm, 463 U. S., at 43, 50. Rule 14e—3(a) may not be "[s]ensibly read" as an exercise of "preventive" authority, ante, at 674, n. 19; it can only be differently so read, contrary to its own terms.

Having already concluded that the Commission lacks the power to redefine fraud, the regulation cannot be sustained on its own reasoning. This would seem a complete answer to whether the Rule is valid because, while we might give deference to the Commission's regulatory constructions of § 14(e), the reasoning used by the regulation itself is in this instance contrary to law and we need give no deference to the Commission's post hoc litigating justifications not reflected in the regulation.

Even on its own merits, the Commission's prophylactic justification fails. In order to be a valid prophylactic regulation, Rule 14e—3(a) must be reasonably designed not merely to prevent any fraud, but to prevent persons from engaging in "fraudulent, deceptive, or manipulative acts or practices, in connection with any tender offer." 15 U. S. C. § 78n(e) (emphasis added). Insofar as Rule 14e—3(a) is designed to prevent the type of misappropriation at issue in this case, such acts are not legitimate objects of prevention because [697] the Commission's misappropriation theory does not represent a coherent interpretation of the statutory "in connection with" requirement, as explained in Part I, supra. Even assuming that a person misappropriating information from the bidder commits fraud on the bidder, the Commission has provided no coherent or consistent explanation as to why such fraud is "in connection with" a tender offer, and thus the Commission may not seek to prevent indirectly conduct which it could not, under its current theory, prohibit directly.^[37]

Finally, even further assuming that the Commission's misappropriation theory is a valid basis for direct liability, I fail to see how Rule 14e—3(a)'s elimination of the requirement of a breach of fiduciary duty is "reasonably designed" to prevent the underlying "fraudulent" acts. The majority's primary argument on this score is that in many cases "`a breach of duty is likely but difficult to prove.' " Ante, at 674 (quoting Reply Brief for United States 16). Although the majority's hypothetical difficulties involved in a tipper-tippee situation might have some merit in the context of "classical" insider trading, there is no reason to suspect similar difficulties in "misappropriation" cases. In such cases, Rule 14e— 3(a) requires the Commission to prove that the defendant "knows or has reason to know" that the nonpublic information upon which trading occurred came from the bidder or an agent of the bidder. Once the source of the information has been identified, it should be a simple task to obtain proof of any breach of duty. After all, it is the bidder itself that was defrauded in misappropriation cases, and there is no reason [698] to suspect that the victim of the fraud would be reluctant to provide evidence against the perpetrator of the fraud.^[38] There being no particular difficulties in proving a breach of duty in such circumstances, a rule removing the requirement of such a breach cannot be said to be "reasonably designed" to prevent underlying violations of the misappropriation theory.

What Rule 14e—3(a) was in fact "designed" to do can be seen from the remainder of the majority's discussion of the Rule. Quoting at length from the Commission's explanation of the Rule in the Federal Register, the majority notes the Commission's concern with "`unfair disparities in market information and market disruption.' " Ante, at 674 (quoting 45 Fed. Reg. 60412 (1980)). In the Commission's further explanation of Rule 14e—3(a)'s purpose—continuing the paragraph partially quoted by the majority—an example of the problem to be addressed is the so-called "stampede effect" [699] based on leaks and rumors that may result from trading on material, nonpublic information. Id., at 60413. The majority also notes (but does not rely on) the Government's contention that it would not be able to prohibit the supposedly problematic practice of "warehousing"—a bidder intentionally tipping allies to buy stock in advance of a bid announcement—if a breach of fiduciary duty were required. Ante, at 672-673, n.17 (citing Reply Brief for United States 17). Given these policy concerns, the majority notes with seeming approval the Commission's justification of Rule 14e—3(a) "as a means necessary and proper to assure the efficacy of Williams Act protections." Ante, at 674.

Although this reasoning no doubt accurately reflects the Commission's purposes in adopting Rule 14e—3(a), it does little to support the validity of that Rule as a means designed to prevent such behavior: None of the above-described acts involve breaches of fiduciary duties, hence a Rule designed to prevent them does not satisfy § 14(e)'s requirement that the Commission's Rules promulgated under that section be "reasonably designed to prevent" acts and practices that "are fraudulent, deceptive, or manipulative." As the majority itself recognizes, there is no "`general duty between all participants in market transactions to forgo actions based on material, nonpublic information,' " and such duty only "`arises from a specific relationship between two parties.' " Ante, at 661 (quoting Chiarella, 445 U. S., at 233). Unfair disparities in market information, and the potential "stampede effect" of leaks, do not necessarily involve a breach of any duty to anyone, and thus are not proper objects for regulation in the name of "fraud" under § 14(e). Likewise (as the Government concedes, Reply Brief for United States 17), "warehousing" is not fraudulent given that the tippees are using the information with the express knowledge and approval of the source of the information. There simply would be no deception in violation of a duty to disclose under such circumstances. Cf. ante, at 654-655 (noting Government's concession [700] that use of bidder's information with bidder's knowledge is not fraudulent under misappropriation theory).

While enhancing the overall efficacy of the Williams Act may be a reasonable goal, it is not one that may be pursued through § 14(e), which limits its grant of rulemaking authority to the prevention of fraud, deceit, and manipulation. As we have held in the context of § 10(b), "not every instance of financial unfairness constitutes fraudulent activity." Chiarella, supra, at 232. Because, in the context of misappropriation cases, Rule 14e—3(a) is not a means "reasonably designed" to prevent persons from engaging in fraud "in connection with" a tender offer, it exceeds the Commission's authority under § 14(e), and respondent's conviction for violation of that Rule cannot be sustained.

III

With regard to respondent's convictions on the mail fraud counts, my view is that they may be sustained regardless of whether respondent may be convicted of the securities fraud counts. Although the issue is highly fact bound, and not independently worthy of plenary consideration by this Court, we have nonetheless accepted the issue for review and therefore I will endeavor to resolve it.

As I read the indictment, it does not materially differ from the indictment in Carpenter v. United States, 484 U. S. 19 (1987). There, the Court was unanimous in upholding the mail fraud conviction, id., at 28, despite being evenly divided on the securities fraud counts, id., at 24. I do not think the wording of the indictment in the current case requires a finding of securities fraud in order to find mail fraud. Certainly the jury instructions do not make the mail fraud count dependent on the securities fraud counts. Rather, the counts were simply predicated on the same factual basis, and just because those facts are legally insufficient to constitute securities fraud does not make them legally insufficient [701] to constitute mail fraud.^[39] I therefore concur in the judgment of the Court as it relates to respondent's mail fraud convictions.

----------

[1] Briefs of amici curiae urging reversal were filed for the American Institute of Certified Public Accountants by Louis A. Craco, Richard I. Miller, and David P. Murray; for the Association for Investment Management and Research by Stuart H. Singer; and for the North American Securities Administrators Association, Inc., et al. by Karen M. O'Brien, Meyer Eisenberg, Louis Loss, and Donald C. Langevoort.

Briefs of amici curiae urging affirmance were filed for Law Professors and Counsel by Richard W. Painter and Douglas W. Dunham; and for the National Association of Criminal Defense Lawyers by Arthur F. Mathews, David M. Becker, Andrew B. Weissman, Robert F. Hoyt, Lisa Kemler, Milton V. Freeman, and Elkan Abramowitz.

[2] As evidence that O'Hagan traded on the basis of nonpublic information misappropriated from his law firm, the Government relied on a conversation between O'Hagan and the Dorsey & Whitney partner heading the firm's Grand Met representation. That conversation allegedly took place shortly before August 26, 1988. See Brief for United States 4. O'Hagan urges that the Government's evidence does not show he traded on the basis of nonpublic information. O'Hagan points to news reports on August 18 and 22, 1988, that Grand Met was interested in acquiring Pillsbury, and to an earlier, August 12, 1988, news report that Grand Met had put up its hotel chain for auction to raise funds for an acquisition. See Brief for Respondent 4 (citing App. 73-74, 78-80). O'Hagan's challenge to the sufficiency of the evidence remains open for consideration on remand.

[3] O'Hagan was convicted of theft in state court, sentenced to 30 months' imprisonment, and fined. See State v. O'Hagan, 474 N. W. 2d 613, 615, 623 (Minn. App. 1991). The Supreme Court of Minnesota disbarred O'Hagan from the practice of law. See In re O'Hagan, 450 N. W. 2d 571 (1990).

[4] See, e. g., United States v. Chestman, 947 F. 2d 551, 566 (CA2 1991) (en banc), cert. denied, 503 U. S. 1004 (1992); SEC v. Cherif, 933 F. 2d 403, 410 (CA7 1991), cert. denied, 502 U. S. 1071 (1992); SEC v. Clark, 915 F. 2d 439, 453 (CA9 1990).

[5] Twice before we have been presented with the question whether criminal liability for violation of § 10(b) may be based on a misappropriation theory. In Chiarella v. United States, 445 U. S. 222, 235-237 (1980), the jury had received no misappropriation theory instructions, so we declined to address the question. See infra, at 661. In Carpenter v. United States, 484 U. S. 19, 24 (1987), the Court divided evenly on whether, under the circumstances of that case, convictions resting on the misappropriation theory should be affirmed. See Aldave, The Misappropriation Theory: Carpenter and Its Aftermath, 49 Ohio St. L. J. 373, 375 (1988) (observing that "Carpenter was, by any reckoning, an unusual case," for the information there misappropriated belonged not to a company preparing to engage in securities transactions, e. g., a bidder in a corporate acquisition, but to the Wall Street Journal).

[6] The Government could not have prosecuted O'Hagan under the classical theory, for O'Hagan was not an "insider" of Pillsbury, the corporation in whose stock he traded. Although an "outsider" with respect to Pillsbury, O'Hagan had an intimate association with, and was found to have traded on confidential information from, Dorsey & Whitney, counsel to tender offer or Grand Met. Under the misappropriation theory, O'Hagan's securities trading does not escape Exchange Act sanction, as it would under Justice Thomas' dissenting view, simply because he was associated with, and gained nonpublic information from, the bidder, rather than the target.

[7] Under the misappropriation theory urged in this case, the disclosure obligation runs to the source of the information, here, Dorsey & Whitney and Grand Met. Chief Justice Burger, dissenting in Chiarella, advanced a broader reading of § 10(b) and Rule 10b—5; the disclosure obligation, as he envisioned it, ran to those with whom the misappropriator trades. 445 U. S., at 240 ("a person who has misappropriated nonpublic information has an absolute duty to disclose that information or to refrain from trading"); see also id., at 243, n. 4. The Government does not propose that we adopt a misappropriation theory of that breadth.

[8] Where, however, a person trading on the basis of material, nonpublic information owes a duty of loyalty and confidentiality to two entities or persons—for example, a law firm and its client—but makes disclosure to only one, the trader may still be liable under the misappropriation theory.

[9] Justice Thomas' evident struggle to invent other uses to which O'Hagan plausibly might have put the nonpublic information, see post, at 685, is telling. It is imaginative to suggest that a trade journal would have paid O'Hagan dollars in the millions to publish his information. See Tr. of Oral Arg. 36-37. Counsel for O'Hagan hypothesized, as a nontrading use, that O'Hagan could have "misappropriat[ed] this information of [his] law firm and its client, deliver[ed] it to [Pillsbury], and suggest[ed] that [Pillsbury] in the future . . . might find it very desirable to use [O'Hagan] for legal work." Id., at 37. But Pillsbury might well have had large doubts about engaging for its legal work a lawyer who so stunningly displayed his readiness to betray a client's confidence. Nor is the Commission's theory "incoherent" or "inconsistent," post, at 680, 692, for failing to inhibit use of confidential information for "personal amusement . . . in a fantasy stock trading game," post, at 685.

[10] As noted earlier, however, see supra, at 654-655, the textual requirement of deception precludes § 10(b) liability when a person trading on the basis of nonpublic information has disclosed his trading plans to, or obtained authorization from, the principal—even though such conduct may affect the securities markets in the same manner as the conduct reached by the misappropriation theory. Contrary to Justice Thomas' suggestion, see post, at 689-691, the fact that § 10(b) is only a partial antidote to the problems it was designed to alleviate does not call into question its prohibition of conduct that falls within its textual proscription. Moreover, once a disloyal agent discloses his imminent breach of duty, his principal may seek appropriate equitable relief under state law. Furthermore, in the context of a tender offer, the principal who authorizes an agent's trading on confidential information may, in the Commission's view, incur liability for an Exchange Act violation under Rule 14e—3(a).

[11] The Eighth Circuit's conclusion to the contrary was based in large part on Dirks `s reiteration of the Chiarella language quoted and discussed above. See 92 F. 3d 612, 618-619 (1996).

[12] The United States additionally argues that Congress confirmed the validity of the misappropriation theory in the Insider Trading and Securities Fraud Enforcement Act of 1988 (ITSFEA), § 2(1), 102 Stat. 4677, note following 15 U. S. C. § 78u—1. See Brief for United States 32-35. ITSFEA declares that "the rules and regulations of the Securities and Exchange Commission under the Securities Exchange Act of 1934 . . . governing trading while in possession of material, nonpublic information are, as required by such Act, necessary and appropriate in the public interest and for the protection of investors." Note following 15 U. S. C. § 78u—1. ITSFEA also includes a new § 20A(a) of the Exchange Act expressly providing a private cause of action against persons who violate the Exchange Act "by purchasing or selling a security while in possession of material, nonpublic information"; such an action may be brought by "any person who, contemporaneously with the purchase or sale of securities that is the subject of such violation, has purchased . . . or sold . . . securities of the same class." 15 U. S. C. § 78t—1(a). Because we uphold the misappropriation theory on the basis of § 10(b) itself, we do not address ITSFEA's significance for cases of this genre.

[13] In relevant part, § 32 of the Exchange Act, as set forth in 15 U. S. C. § 78ff(a), provides:

"Any person who willfully violates any provision of this chapter . . . or any rule or regulation thereunder the violation of which is made unlawful or the observance of which is required under the terms of this chapter . . . shall upon conviction be fined not more than $1,000,000, or imprisoned not more than 10 years, or both . . . ; but no person shall be subject to imprisonment under this section for the violation of any rule or regulation if he proves that he had no knowledge of such rule or regulation."

[14] The statute provides no such defense to imposition of monetary fines. See ibid.

[15] In addition to § 14(e), the Williams Act and the 1970 amendments added to the Exchange Act the following provisions concerning disclosure: § 13(d), 15 U. S. C. § 78m(d) (disclosure requirements for persons acquiring more than five percent of certain classes of securities); § 13(e), 15 U. S. C. § 78m(e) (authorizing Commission to adopt disclosure requirements for certain repurchases of securities by issuer); § 14(d), 15 U. S. C. § 78n(d) (disclosure requirements when tender offer results in offer or owning more than five percent of a class of securities); § 14(f),15 U. S. C. § 78n(f) (disclosure requirements when tender offer results in new corporate directors constituting a majority).

[16] The Rule thus adopts for the tender offer context a requirement resembling the one Chief Justice Burger would have adopted in Chiarella for misappropriators under § 10(b). See supra, at 655, n. 6.

[17] The Government draws our attention to the following measures: 17 CFR § 240.15c2-1 (1970) (prohibiting a broker-dealer's hypothecation of a customer's securities if hypothecated securities would be commingled with the securities of another customer, absent written consent); § 240.15c2-3 (prohibiting transactions by broker-dealers in unvalidated German securities); § 240.15c2-4 (prohibiting broker-dealers from accepting any part of the sale price of a security being distributed unless the money received is promptly transmitted to the persons entitled to it); § 240.15c2-5 (requiring broker-dealers to provide written disclosure of credit terms and commissions in connection with securities sales in which broker-dealers extend credit, or participate in arranging for loans, to the purchasers). See Brief for United States 39, n. 22.

[18] We leave for another day, when the issue requires decision, the legitimacy of Rule 14e—3(a) as applied to "warehousing," which the Government describes as "the practice by which bidders leak advance information of a tender offer to allies and encourage them to purchase the target company's stock before the bid is announced." Reply Brief 17. As we observed in Chiarella, one of the Commission's purposes in proposing Rule 14e—3(a) was "to bar warehousing under its authority to regulate tender offers." 445 U. S., at 234. The Government acknowledges that trading authorized by a principal breaches no fiduciary duty. See Reply Brief 17. The instant case, however, does not involve trading authorized by a principal; therefore, we need not here decide whether the Commission's proscription of warehousing falls within its § 14(e) authority to define or prevent fraud.

[19] The Commission's power under § 10(b) is more limited. See supra, at 651 (Rule 10b—5 may proscribe only conduct that § 10(b) prohibits).

[20] Justice Thomas' dissent urges that the Commission must be precise about the authority it is exercising—that it must say whether it is acting to "define" or to "prevent" fraud—and that in this instance it has purported only to define, not to prevent. See post, at 696. Justice Thomas sees this precision in Rule 14e—3(a)'s words: "it shall constitute a fraudulent . . . act . . . within the meaning of section 14(e) . . . ." We do not find the Commission's Rule vulnerable for failure to recite as a regulatory preamble: We hereby exercise our authority to "define, and prescribe means reasonably designed to prevent, . . . [fraudulent] acts." Sensibly read, the Rule is an exercise of the Commission's full authority. Logically and practically, such a rule may be conceived and defended, alternatively, as definitional or preventive.

[21] Justice Thomas opines that there is no reason to anticipate difficulties in proving breach of duty in "misappropriation" cases. "Once the source of the [purloined] information has been identified," he asserts, "it should be a simple task to obtain proof of any breach of duty." Post, at 697. To test that assertion, assume a misappropriating partner at Dorsey & Whitney told his daughter or son and a wealthy friend that a tender for Pillsbury was in the offing, and each tippee promptly purchased Pillsbury stock, the child borrowing the purchase price from the wealthy friend. Justice Thomas' confidence, post, at 698, n. 12, that "there is no reason to suspect that the tipper would gratuitously protect the tippee," seems misplaced.

[22] Justice Thomas insists that even if the misappropriation of information from the bidder about a tender offer is fraud, the Commission has not explained why such fraud is "in connection with" a tender offer. Post, at 697, 698. What else, one can only wonder, might such fraud be "in connection with"?

[23] Repeating the argument it made concerning the misappropriation theory, see supra, at 665, n. 11, the United States urges that Congress confirmed Rule 14e—3(a)'s validity in ITSFEA, 15 U. S. C. § 78u—1. See Brief for United States 44-45. We uphold Rule 14e—3(a) on the basis of § 14(e) itself and need not address ITSFEA's relevance to this case.

[24] As to O'Hagan's scienter argument, we reiterate that 15 U. S. C. § 78ff(a)requires the Government to prove "willful[l]violat[ion]" of the securities laws, and that lack of knowledge of the relevant rule is an affirmative defense to a sentence of imprisonment. See supra, at 665-666.

[25] The Court of Appeals reversed respondent's money laundering convictions on similar reasoning. See 92 F. 3d, at 628. Because the United States did not seek review of that ruling, we leave undisturbed that portion of the Court of Appeals' judgment.

[26] Justice Thomas finds O'Hagan's convictions on the mail fraud counts, but not on the securities fraud counts, sustainable. Post, at 700-701. Under his view, securities traders like O'Hagan would escape SEC civil actions and federal prosecutions under legislation targeting securities fraud, only to be caught for their trading activities in the broad mail fraud net. If misappropriation theory cases could proceed only under the federal mail and wire fraud statutes, practical consequences for individual defendants might not be large, see Aldave, 49 Ohio St. L. J., at 381, and n. 60; however, "proportionally more persons accused of insider trading [might] be pursued by a U. S. Attorney, and proportionally fewer by the SEC," id., at 382. Our decision, of course, does not rest on such enforcement policy considerations.

[27] Of course, the "use" to which one puts misappropriated property need not be one designed to bring profit to the misappropriator: Any "fraudulent appropriation to one's own use" constitutes embezzlement, regardless of what the embezzler chooses to do with the money. See, e. g., Logan v. State, 493 P. 2d 842, 846 (Okla. Crim. App. 1972) ("Any diversion of funds held in trust constitutes embezzlement whether there is direct personal benefit or not as long as the owner is deprived of his money").

[28] Indeed, even if O'Hagan or someone else thereafter used the information to trade, the misappropriation would have been complete before the trade and there should be no § 10(b) liability. The most obvious realworld example of this scenario would be if O'Hagan had simply tipped someone else to the information. The mere act of passing the information along would have violated O'Hagan's fiduciary duty and, if undisclosed, would be an "embezzlement" of the confidential information, regardless of whether the tippee later traded on the information.

[29] The majority is apparently unimpressed by the example of a misappropriator using embezzled information for personal amusement in a fantasy stock trading game, finding no need for the Commission to "inhibit" such recreational uses. Ante, at 657, n. 8. This argument, of course, misses the point of the example. It is not that such a use does or should violate the securities laws yet is not covered by the Commission's theory; rather, the example shows that the misappropriation of information is not "only" or "inherently" tied to securities trading, and hence the misappropriation of information, whatever its ultimate use, fails the Commission's own test under the "in connection with" requirement of § 10(b) and Rule 10b—5.

[30] Similarly, the majority's assertion that the alternative uses of misappropriated information are not as profitable as use in securities trading, ante, at 657, n. 8, is speculative at best. We have no idea what is the best or most profitable use of misappropriated information, either in this case or generally. We likewise have no idea what is the best use of other forms of misappropriated property, and it is at least conceivable that the best use of embezzled money, or securities themselves, is for securities trading. If the use of embezzled money to purchase securities is "sufficiently detached," ante, at 657, from a securities transaction, then I see no reason why the non-"inherent" use of information for securities trading is not also "sufficiently detached" under the Government's theory. In any event, I am at a loss to find in the statutory language any hint of a "best-use" requirement for setting the requisite connection between deception and the purchase or sale of securities.

The majority's further claim that it is unremarkable that "a rule suitably applied to the fraudulent uses of certain kinds of information would be stretched beyond reason were it applied to the fraudulent use of money," ibid., is itself remarkable given that the only existing "rule" is Rule 10b—5, which nowhere confines itself to information and, indeed, does not even contain the word. And given that the only "reason" offered by the Government in support of its misappropriation theory applies (or fails to apply) equally to money or to information, the application of the Government's theory in this case is no less "beyond reason" than it would be as applied to financial embezzlement.

[31] See Tr. of Oral Arg. 9 (Government conceding that, "just as in [Carpenter v. United States, 484 U. S. 19 (1987)], if [the defendant] had gone to the Wall Street Journal and said, look, you know, you're not paying me very much. I'd like to make a little bit more money by buying stock, the stocks that are going to appear in my Heard on the Street column, and the Wall Street Journal said, that's fine, there would have been no deception of the Wall Street Journal").

[32] That the dishonesty aspect of misappropriation might be eliminated via disclosure or authorization is wholly besides the point. The dishonesty in misappropriation is in the relationship between the fiduciary and the principal, not in any relationship between the misappropriator and the market. No market transaction is made more or less honest by disclosure to a third-party principal, rather than to the market as a whole. As far as the market is concerned, a trade based on confidential information is no more "honest" because some third party may know of it so long as those on the other side of the trade remain in the dark.

[33] The majority's statement, by arguing that market advantage is gained "through" deception, unfortunately seems to embrace an error in logic: Conflating causation and correlation. That the misappropriator may both deceive the source and "simultaneously" hurt the public no more shows a causal "connection" between the two than the fact that the sun both gives some people a tan and "simultaneously" nourishes plants demonstrates that melanin production in humans causes plants to grow. In this case, the only element common to the deception and the harm is that both are the result of the same antecedent cause—namely, using nonpublic information. But such use, even for securities trading, is not illegal, and the consequential deception of the source follows an entirely divergent branch of causation than does the harm to the public. The trader thus "gains his advantageous market position through " the use of nonpublic information, whether or not deception is involved; the deception has no effect on the existence or extent of his advantage.

[34] That the Commission may purport to be interpreting its own Rule, rather than the statute, cannot provide it any greater leeway where the Rule merely repeats verbatim the statutory language on which the entire question hinges. Furthermore, as even the majority recognizes, Rule 10b—5 may not reach beyond the scope of § 10(b), ante, at 651, and thus the Commission is obligated to explain how its theory fits within its interpretation of § 10(b) even if it purports to be interpreting its own derivative rule.

[35] Although the majority leaves open the possibility that Rule 14e—3(a) may be justified as a means of preventing "warehousing," it does not rely on that justification to support its conclusion in this case. Suffice it to say that the Commission itself concedes that warehousing does not involve fraud as defined by our cases, see Reply Brief for United States 17, and thus preventing warehousing cannot serve to justify Rule 14e—3(a).

[36] Even were § 14(e)'s defining authority subject to the construction given it by the Commission, there are strong constitutional reasons for not so construing it. A law that simply stated "it shall be unlawful to do 'X', however 'X' shall be defined by an independent agency," would seem to offer no "intelligible principle" to guide the agency's discretion and would thus raise very serious delegation concerns, even under our current jurisprudence, J. W. Hampton, Jr., & Co. v. United States, 276 U. S. 394, 409 (1928). See also Field v. Clark, 143 U. S. 649, 693-694 (1892) (distinguishing between making the law by determining what it shall be, and executing the law by determining facts on which the law's operation depends). The Commission's interpretation of § 14(e) would convert it into precisely the type of law just described. Thus, even if that were a plausible interpretation, our usual practice is to avoid unnecessary interpretations of statutory language that call the constitutionality of the statute into further serious doubt.

[37] I note that Rule 14e—3(a) also applies to persons trading upon information obtained from an insider of the target company. Insofar as the Rule seeks to prevent behavior that would be fraudulent under the "classical theory" of insider trading, this aspect of my analysis would not apply. As the majority notes, however, the Government "could not have prosecuted O'Hagan under the classical theory," ante, at 653, n. 5, hence this proviso has no application to the present case.

[38] Even where the information is obtained from an agent of the bidder, and the tippee claims not to have known that the tipper violated a duty, there is still no justification for Rule 14e—3(a). First, in such circumstances the tipper himself would have violated his fiduciary duty and would be liable under the misappropriation theory, assuming that theory were valid. Facing such liability, there is no reason to suspect that the tipper would gratuitously protect the tippee. And if the tipper accurately testifies that the tippee was (falsely) told that the information was passed on without violating the tipper's own duties, one can question whether the tippee has in fact done anything illegal, even under the Commission's misappropriation theory. Given that the fraudulent breach of fiduciary duty would have been complete at the moment of the tip, the subsequent trading on that information by the tippee might well fail even the Commission's own construction of the "in connection with" requirement. See supra, at 683-687. Thus, even if the tipper might, in some circumstances, be inclined to protect the tippee, see ante, at 675-676, n. 20, it is doubtful that the tippee would have violated the misappropriation theory in any event, and thus preventing such nonviolations cannot justify Rule 14e— 3(a). Second, even were this scenario a legitimate concern, it would at most justify eliminating the requirement that the tippee "know" about the breach of duty. It would not explain Rule 14e—3(a)'s elimination of the requirement that there be such a breach.

[39] While the majority may find it strange that the "mail fraud net" is broader reaching than the securities fraud net, ante, at 678, n. 25, any such supposed strangeness—and the resulting allocation of prosecutorial responsibility between the Commission and the various United States Attorneys—is no business of this Court, and can be adequately addressed by Congress if it too perceives a problem regarding jurisdictional boundaries among the Nation's prosecutors. That the majority believes that, upon shifting from securities fraud to mail fraud prosecutions, the "practical consequences for individual defendants might not be large," ibid., both undermines the supposed policy justifications for today's decision and makes more baffling the majority's willingness to go to such great lengths to save the Commission from itself.