The facts set forth in paragraphs 23 and 24, initially alleged in support of the Union's federal antitrust claim, are realleged in each of the other claims for relief: breach of collective-bargaining agreements (¶¶ 29-31); intentional interference with contractual relations (¶¶ 32-35); intentional interference with business relationships (¶¶ 36-39); and violation of the California antitrust statute (¶¶ 40-43).

For example, it is alleged that defendants breached their collective-bargaining agreements "by failing to pay agreed-upon wages, by failing to use the hiring hall, by failing to pay Trust Fund contributions, by failing to observe other terms and conditions of employment, and by generally weakening the good faith requirement of the collective bargaining agreements"; that defendants improperly changed their names and corporate status and made use of so-called "double breasted operations"; and that they encouraged nonmembers of Associated to refuse to enter into collective-bargaining agreements with the Union.

The word "coerced" did not appear in the complaint as originally filed. Even as amended after the filing of motions to dismiss, the complaint does not allege that the defendants used any coercion to persuade nonmembers of Associated to refuse to enter into collective-bargaining agreements with the Union (¶ 24(3)). The complaint alleges neither the identity nor the number of landowners, general contractors, or others who were coerced into making contracts with nonunion firms.

Paragraph 25, which describes the effect of the conspiracy, reads in full as follows:
"The purpose and effect of the above described activities, plan and conspiracy are oppressive, unreasonable, and illegal, and are in restraint of trade and an unlawful interference and restraint of the free exercise of the business activities of plaintiffs and each of them, all in violation of 15 U.S.C. § 1. The purpose and effect of the above described activities, plan and conspiracy, in addition, are to weaken, destroy, and restrain the trade of certain contractors, both members of the Associated General Contractors of California, Inc. and non-members, who are `memorandum contractors,' who have faithfully performed the terms and conditions set out in the master collective bargaining agreements described above. The effect of this restraint on trade is to further weaken and destroy plaintiffs in this matter. These activities are in restraint of the free exercise of plaintiffs' trade and an interference therein, all in violation of 15 U.S.C. § 1." App. E to Pet. for Cert. 20-21.

Plaintiffs do not seek injunctive relief under § 16 of the Clayton Act, 15 U.S.C. § 26, and they do not ask us to consider whether they have standing to request such relief.

An order dismissing the federal antitrust claim and the state-law claims was filed on August 4, 1975, and an amended order dismissing the entire complaint was entered on September 10, 1975. The District Court had initially stayed the breach-of-contract claim for 120 days pending grievance and arbitration procedures. On reconsideration it also dismissed the breach-of-contract claim, deciding that the suit had been prematurely filed.

Addressing the federal antitrust claim, the District Court concluded:
"The essence of plaintiffs' claim seems to be that defendants violated the antitrust laws insofar as they declined to enter into agreements with plaintiffs to deal only with subcontractors which were signatories to contracts with plaintiffs, precisely the type of agreement which subjected the union in Connell to antitrust liability." 404 F. Supp., at 1070.
The District Court reasoned that the employers' refusal to enter into such an agreement could not provide the basis for an antitrust claim.

The Court of Appeals affirmed the dismissal of all other claims.

The Court of Appeals majority read subparagraph (4) of paragraph 24, quoted supra, at 522, as though it alleged that the defendants had coerced landowners and other persons who let construction contracts "to hire only construction firms, primarily subcontractors, who had not signed with the Unions." 648 F.2d, at 532 (emphasis added); see also id., at 544 (denying petition for rehearing). The word "only" does not appear in the amended complaint, and it implies that the defendants' activities gave rise to a broader restraint than was actually alleged.
The majority read subparagraph (5) of paragraph 24 to charge that defendants had "coerced and aided each other to subcontract only with subcontractors who had not signed with the Unions." Id., at 531 (emphasis added). Again using the word "only," which does not appear in the complaint itself, the majority characterized the defendants' alleged activities as "very similar to a concerted refusal to deal, or a group boycott." Ibid. It concluded that the allegations "present virtually the obverse of the situation described in Connell": the conspiracy, if successful, "would effectively lock union-signatory subcontractors out of a portion of the market for carpentry work." Id., at 532.

See Tugboat, Inc. v. Mobile Towing Co., 534 F.2d 1172, 1176-1177 (CA5 1976); International Assn. of Heat Frost Insulators v. United Contractors Assn., 483 F.2d 384, 397-398 (CA3 1973).
Circuit Judge Sneed dissented. He first rejected the majority's characterization of the complaint, agreeing instead with the District Court. Second, assuming that the complaint alleged a boycott of certain employers, he concluded that neither the employees of a victim of the boycott nor their collective-bargaining representative had standing to assert the antitrust claim. Finally, he concluded that an injury that affected only the Union's organizational and representational activity was remediable under the labor laws rather than the antitrust laws.
The Court of Appeals denied the petition for rehearing and rehearing en banc on May 22, 1981. Accompanying the order was a statement by the majority rebutting the petitioners' assertion that the opinion rendered multiemployer bargaining units unlawful, and a dissent by Circuit Judge Sneed. 648 F.2d, at 543, 545.

The Union had an adequate opportunity to amend its pleading to add factual allegations demonstrating that the District Court's decision to dismiss the complaint was based on a misunderstanding of its antitrust claim.

In analyzing the antitrust allegations in the amended complaint, we therefore construe the references to "contractors and subcontractors who are not signatories to collective bargaining agreements" as referring to completely independent nonunion firms rather than to operations covertly controlled by one or more defendants.

The Court of Appeals did not reverse the District Court's dismissal of the complaint with regard to these allegations. 648 F.2d, at 531-532, 537, 540.

See Brief for Respondents 37. There is no allegation of wrongful conduct directed at nonunion subcontracting firms. We therefore assume that, if any nonunion firms refused to bargain with the Union because of the conspiracy, they did so because they were rewarded with business they would not otherwise have obtained. Thus, nonunion firms could not be considered victims of the conspiracy; rather, they appear to have been its indirect beneficiaries. None are named either as defendants or as co-conspirators.
The amended complaint also does not allege any restraint on competition in the market for labor union services. Unlike the two cases involving union plaintiffs cited by the Court of Appeals, see n. 10, supra, in this case there is no claim that competition between rival unions has been injured or even that any rival unions exist.

The complaint does not specify the nature of the "coercion." It does not, for example, allege that the defendants refused to deal with all members of either of the two classes of persons against whom coercion was applied. Indeed, it is highly improbable that the defendants — all of whom are signatories to union contracts — would refuse to deal with all of their customers and potential customers in an attempt to divert all of their business to nonunion firms.

There is no allegation that any person subjected to coercion was required to deal exclusively with nonunion firms.

Had the District Court required the Union to describe the nature of the alleged coercion with particularity before ruling on the motion to dismiss, it might well have been evident that no violation of law had been alleged. In making the contrary assumption for purposes of our decision, we are perhaps stretching the rule of Conley v. Gibson, 355 U.S. 41, 47-48 (1957), too far. Certainly in a case of this magnitude, a district court must retain the power to insist upon some specificity in pleading before allowing a potentially massive factual controversy to proceed.

Although we do not know what kind of coercion defendants allegedly employed, we assume for purposes of decision that it had a predatory "nature or character," Klors, Inc. v. Broadway-Hale Stores, Inc., 359 U.S., at 211, and that it would "cripple the freedom of traders and thereby restrain their ability to sell in accordance with their own judgment." Kiefer-Stewart Co. v. Joseph E. Seagram Sons, Inc., 340 U.S. 211, 213 (1951).

In Mandeville Island Farms, Inc. v. Sugar Co., 334 U.S. 219 (1948), the Court held that growers of sugar beets could maintain a treble-damages action against refiners who had allegedly conspired to fix the price that they would pay for the beets. Although previous price-fixing cases had involved agreements among sellers to fix sales prices, the Court readily concluded that the Act applied equally to an agreement among competing buyers to fix purchase prices. The Court stated:
"The statute does not confine its protection to consumers, or to purchasers, or to competitors, or to sellers. Nor does it immunize the outlawed acts because they are done by any of these. Cf. United States v. Socony-Vacuum Oil Co., 310 U.S. 150; American Tobacco Co. v. United States, 328 U.S. 781. The Act is comprehensive in its terms and coverage, protecting all who are made victims of the forbidden practices by whomever they may be perpetrated." Id., at 236.
Similarly broad language was used in later cases holding that actions could be maintained by consumers, Reiter v. Sonotone Corp., 442 U.S. 330, 337-338 (1979), by a foreign government, Pfizer Inc. v. India, 434 U.S. 308, 313-314 (1978), and by the direct victim of a boycott. Blue Shield of Virginia v. McCready, 457 U.S. 465, 472-473 (1982). In each of those cases, however, the actual plaintiff was directly harmed by the defendants' unlawful conduct. The paraphrasing of the language of § 4 in those opinions added nothing to the even broader language that the statute itself contains.

See 21 Cong. Rec. 1767-1768, 2455-2456, 2459, 2615, 3147-3148 (1890). The original proposal, which merely allowed recovery of the amount of actual enhancement in price, was successively amended to authorize double-damages and then treble-damages recoveries, in order to provide otherwise remediless small consumers with an adequate incentive to bring suit. Id., at 1765, 2455, 3145. The same purpose was served by the special venue provisions, the provision for the recovery of attorney's fees, and the elimination of any requirement that the amount in controversy exceed the jurisdictional threshold applicable in other federal litigation. See, e. g., id., at 2612, 3149. Moreover, changes in the description of the remedy extended the section's coverage beyond price fixing.

See, e. g., id., at 2456, 2459, 3151-3152.

Page 531 Id., at 2456. Senator Sherman added: "The purpose of this bill is to enable the courts of the United States to apply the same remedies against combinations which injuriously affect the interests of the United States that have been applied in the several States to protect local interests." Ibid.; see also id., at 2459, 3149, 3151-3152. Although Members of Congress referred particularly to common-law definitions of "monopoly" and "restraint of trade," they appear to have been generally aware that the statute would be construed by common-law courts in accordance with traditional canons. For example, at the beginning of the debate on the Sherman Act, one Senator cautioned his colleagues:
"A careful analysis of the terms of the bill is essential. We must know what it means, what its legal effect is, if we give force to it as it is written. . . . We must adopt, therefore, the known methods of the courts in determining what the bill means." Id., at 1765.

For example, the State Constitution of Illinois, adopted in 1870, provided: "Every person ought to find a certain remedy in the laws for all injuries and wrongs which he may receive in his person, property or reputation . . . ." Art. II, § 19. Comparable provisions were found in the State Constitutions of Arkansas, Connecticut, Delaware, Indiana, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Minnesota, Mississippi, New Hampshire, Ohio, and Vermont. See generally F. Hough, American Constitutions (1871).

One treatise stated: "Natural, proximate, and legal results are all that damages can be recovered for, even under a statute entitling one `to recover any damage.'" 3 J. Lawson, Rights, Remedies, and Practice 1740 (1890). Another leading treatise explained:
"The chief and sufficient reason for this rule is to be found in the impossibility of tracing consequences through successive steps to the remote cause, and the necessity of pausing in the investigation of the chain of events at the point beyond which experience and observation convince us we cannot press our inquiries with safety." T. Cooley, Law of Torts 73 (2d ed. 1888).

In torts, a leading treatise on damages set forth the general principle that, " [w]here the plaintiff sustains injury from the defendant's conduct to a third person, it is too remote, if the plaintiff sustains no other than a contract relation to such a third person, or is under contract obligation on his account, and the injury consists only in impairing the ability or inclination of such person to perform his part, or in increasing the plaintiff's expense or labor of fulfilling such contract, unless the wrongful act is willful for that purpose." Thus, A, who had agreed with a town to support all the town paupers for a specific period, in return for a fixed sum, had no cause of action against S for assaulting and beating one of the paupers, thereby putting A to increased expense. Similarly, a purchaser under an output contract with a manufacturer had no right of recovery against a trespasser who stopped the company's machinery, and a creditor could not recover against a person who had forged a note, causing diminution in the dividends from an estate. 1 J. Sutherland, Law of Damages 55-56 (1882) (emphasis in original, footnote omitted).
Similarly, in contract, the common-law courts drew a distinction between direct and consequential damages; the latter had to be specifically included in the contract to be recoverable. See id., at 74-93; 1 T. Sedgwick, Measure of Damages 203-244 (8th ed. 1891) (discussing the rule of Hadley v. Baxendale, 9 Exch. 341, 156 Eng. Rep. 145 (1854)).

The common law required the plaintiff to prove, with certainty, both the existence of damages and the causal connection between the wrong and the injury. No damages could be recovered for uncertain, conjectural, or speculative losses. See generally cases cited in F. Bohlen, Cases on the Law of Torts 292-312 (2d ed. 1925) (cases alleging emotional harm to plaintiff). Even if the injury was easily provable, there would be no recovery if the plaintiff could not sufficiently establish the causal connection. See 1 Sutherland, supra n. 25, at 94-126; 1 Sedgwick, supra n. 25, at 245-294.

See, e. g., Winterbottom v. Wright, 10 M. W. 109, 152 Eng. Rep. 402 (Ex. 1842).

See n. 22, supra. The common law, of course, is an evolving body of law. We do not mean to intimate that the limitations on damages recoveries found in common-law actions in 1890 were intended to serve permanently as limits on Sherman Act recoveries. But legislators familiar with these limits could hardly have intended the language of § 7 to be taken literally.

See also Ames v. American Telephone Telegraph Co., 166 F. 820 (CC Mass. 1909). Applying "ordinary principles of law" to the general language of the statute, the court held that a stockholder had no legally cognizable antitrust claim against defendants for illegally acquiring the corporation, thereby rendering plaintiff's stock worthless. Plaintiff's claim was not distinguishable from any injury sustained by the company itself. Therefore, the court stated, a contrary result would "subject the defendant not merely to treble damages, but to sextuple damages, for the same unlawful act." Id., at 823.

The Court held in that case that the plaintiff shippers could recover damages from the defendant railroad for charging an excessive freight rate, even though they had been able to pass on the damage to their purchasers. Justice Holmes wrote that the law holds the defendant "liable if proximately the plaintiff has suffered a loss," but "does not attribute remote consequences to a defendant." 245 U.S., at 533-534.

The label "antitrust standing" has traditionally been applied to some of the elements of this inquiry. As commentators have observed, the focus of the doctrine of "antitrust standing" is somewhat different from that of standing as a constitutional doctrine. Harm to the antitrust plaintiff is sufficient to satisfy the constitutional standing requirement of injury in fact, but the court must make a further determination whether the plaintiff is a proper party to bring a private antitrust action. See Berger Bernstein, An Analytical Framework for Antitrust Standing, 86 Yale L. J. 809, 813, n. 11 (1977); Pollock, Standing to Sue, Remoteness of Injury, and the Passing-On Doctrine, 32 A.B.A. Antitrust L. J. 5, 6-7 (1966).

In his comment, Mahoney v. Beatman: A Study in Proximate Cause, 39 Yale L. J. 532, 533 (1930), Leon Green noted: "Legal theory is too rich in content not to afford alternative ways, and frequently several of them, for stating an acceptable judgment." Earlier, in his Rationale of Proximate Cause 135-136 (1927) (footnote omitted), Green had written:
"`Cause,' although irreducible in its concept, could not escape the ruffles and decorations so generously bestowed: remote, proximate, direct, immediate, adequate, efficient, operative, inducing, moving, active, real, effective, decisive, supervening, primary, original, contributory, ultimate, concurrent, causa causans, legal, responsible, dominating, natural, probable, and others. The difficulty now is in getting any one to believe that so simple a creature could have been so extravagantly garbed."

Some courts have focused on the directness of the injury, e. g., Loeb v. Eastman Kodak Co., 183 F. 704, 709 (CA3 1910); Productive Inventions, Inc. v. Trico Products Corp., 224 F.2d 678, 679 (CA2 1955), cert. denied, 350 U.S. 936 (1956); Volasco Products Co. v. Lloyd A. Fry Roofing Co., 308 F.2d 383, 394-395 (CA6 1962), cert. denied, 372 U.S. 907 (1963). Others have applied the requirement that the plaintiff must be in the "target area" of the antitrust conspiracy, that is, the area of the economy which is endangered by a breakdown of competitive conditions in a particular industry. E. g., Pan-Islamic Trade Corp. v. Exxon Corp., 632 F.2d 539, 546-547 (CA5 1980); Engine Specialties, Inc. v. Bombardier Ltd., 605 F.2d 1, 17-18 (CA1 1979); Calderone Enterprises Corp. v. United Artists Theater Circuit, Inc., 454 F.2d 1292, 1292-1295 (CA2 1971). Another Court of Appeals has asked whether the injury is "arguably within the zone of interests protected by the antitrust laws." Malamud v. Sinclair Oil Corp., 521 F.2d 1142, 1151-1152 (CA6 1975). See generally Berger Bernstein, supra n. 31.
As a number of commentators have observed, these labels may lead to contradictory and inconsistent results. See Berger Bernstein, supra n. 31, at 835, 843; Handler, The Shift From Substantive to Procedural Innovations in Antitrust Suits, 71 Colum. L. Rev. 1, 27-31 (1971); Sherman, Antitrust Standing: From Leob to Malamud, 51 N.Y. U. L. Rev. 374, 407 (1976) ("it is simply not possible to fashion an across-the-board and easily applied standing rule which can serve as a tool of decision for every case"). In our view, courts should analyze each situation in light of the factors set forth in the text infra.

Cf. Blue Shield of Virginia v. McCready, 457 U.S., at 477-478, n. 13 (discussing elusiveness of test of proximate cause); Palsgraf v. Long Island R. Co., 248 N.Y. 339, 162 N.E. 99 (1928); id., at 351-352, 162 N.E., at 103 (Andrews, J., dissenting) ("What is a cause in a legal sense, still more what is a proximate cause, depend in each case upon many considerations . . . . What we do mean by the word `proximate' is, that because of convenience, of public policy, of a rough sense of justice, the law arbitrarily declines to trace a series of events beyond a certain point").

It is well settled that a defendant's specific intent may sometimes be relevant to the question whether a violation of law has been alleged. See United States v. Columbia Steel Co., 334 U.S. 495, 522 (1948). Moreover, there no doubt are cases in which such an allegation would adequately support a plaintiff's claim under § 4. Cf. Handler, supra n. 33, at 30 (specific intent of defendant to cause injury to a particular class of persons should "ordinarily be dispositive" in creating standing to sue); Lytle Purdue, Antitrust Target Area Under Section 4 of the Clayton Act: Determination of Standing in Light of the Alleged Antitrust Violation, 25 Am. U. L. Rev. 795, 814-816 (1976) (suggesting that standing in a group boycott situation should be based on the purpose of the boycott).

See Sherman, supra n. 33, at 389-391, citing Billy Baxter, Inc. v. Coca-Cola Co., 431 F.2d 183, 189 (CA2 1970), cert. denied, 401 U.S. 923 (1971).

In McCready we rejected the contention that, because there was no specific intent to harm the plaintiff, her injury was thereby rendered remote. This case presents a different question, but in neither case is the motive allegation of controlling importance.

See United States v. Topco Associates, Inc., 405 U.S. 596, 610 (1972) ("Antitrust laws in general, and the Sherman Act in particular, are the Magna Carta of free enterprise. They are as important to the preservation of economic freedom and our free-enterprise system as the Bill of Rights is to the protection of our fundamental personal freedoms. And the freedom guaranteed each and every business, no matter how small, is the freedom to compete — to assert with vigor, imagination, devotion, and ingenuity whatever economic muscle it can muster").

McCready, a Blue Shield subscriber, alleged that Blue Shield and the Neuropsychiatric Society of Virginia, Inc., had unlawfully conspired to restrain competition in the market for psychotherapeutic services by providing insurance coverage only for consumers who patronized psychiatrists, not psychologists. McCready obtained services from a psychologist and was denied reimbursement.

Moreover, it has not even alleged any marketwide restraint of trade. The allegedly unlawful conduct involves predatory behavior directed at "certain" parties, rather than a claim that output has been curtailed or prices enhanced throughout an entire competitive market.

In Mine Workers v. Pennington, 381 U.S. 657, 664 (1965), the Court recognized that wages lie at the heart of the subjects of mandatory collective bargaining, and that "the elimination of competition based on wages among the employers in the bargaining unit," which directly benefits the union, also has an effect on competition in the product market. See generally Leslie, Principles of Labor Antitrust, 66 Va. L. Rev. 1183, 1185-1188 (1980); Winter, Collective Bargaining and Competition: The Application of Antitrust Standards to Union Activities, 73 Yale L. J. 14, 17-20, 28-30 (1963).

See, e. g., Coronado Coal Co. v. Mine Workers, 268 U.S. 295, 310 (1925) (applying Sherman Act to alleged conspiracy by unions involved in labor dispute to restrain interstate trade in coal); Loewe v. Lawlor, 208 U.S. 274 (1908) (applying Sherman Act to boycott by labor organization seeking to unionize plaintiff's hat factory); Cox, Labor and the Antitrust Laws — A Preliminary Analysis, 104 U. Pa. L. Rev. 252, 256-262 (1955); Meltzer, Labor Unions, Collective Bargaining, and the Antitrust Laws, 32 U. Chi. L. Rev. 659, 661-666 (1965); Winter, supra n. 41, at 30-38.

See 29 U.S.C. § 52 (statutory labor exemption); Mine Workers v. Pennington, supra; Meat Cutters v. Jewel Tea Co., 381 U.S. 676 (1965) (nonstatutory exemption). In this case we need not reach petitioner's contentions that the alleged activities are within the statutory and nonstatutory labor exemptions.

There is a parallel between these allegations and the claim in Connell Construction Co. v. Plumbers Steamfitters, 421 U.S. 616 (1975). The plaintiff in that case, a general building contractor, was coerced by the defendant union into signing an agreement not to deal with nonunion subcontractors. Similarly, in the McCready case, the plaintiff was the direct victim of unlawful coercion. As the Court noted, "McCready did not yield to Blue Shield's coercive pressure, and bore Blue Shield's sanction in the form of an increase in the net cost of her psychologist's services." 457 U.S., at 483. Her status was thus comparable to that of a contracting or subcontracting firm that refused to yield to the defendants' coercive practices and therefore suffered whatever sanction that coercion imposed. Like McCready, and like Connell Construction Co., such a firm could maintain an action against the defendants. In contrast, the Union is neither a participant in the market for construction contracts or subcontracts nor a direct victim of the defendants' coercive practices. We therefore need not decide whether the direct victim of a boycott, who suffers a type of injury unrelated to antitrust policy, may recover damages when the ultimate purpose of the boycott is to restrain competition in the relevant economic market.

Its brief merely echoes the Court of Appeals' description of its allegations: "the Unions have been injured in their business, i. e., organizing carpentry industry employees, negotiating and policing collective bargaining agreements, and securing jobs for their members." Brief for Respondents 25-26.

Because of the absence of specific allegations, we can only speculate about the specific components of the Union's claim. If the Union asserts that its attempts to organize previously nonunion firms have been frustrated because nonunion firms wish to continue to obtain business from those subjected to coercion by the defendants, its harm stems most directly from the conduct of persons who are not victims of the conspiracy. See n. 14, supra. If the Union claims that dues payments were adversely affected because employees had less incentive to join the Union in light of expanding nonunion job opportunities, its damage is more remote than the harm allegedly suffered by unionized subcontractors. The same is true if the Union contends that revenues from dues payments declined because its members lost jobs or wages because their unionized employers lost business. That harm, moreover, is even more indirect than the already indirect injury to its members, yet a number of decisions have denied standing to employees with merely derivative injuries. See, e. g., Pitchford v. PEPI, Inc., 531 F.2d 92, 97 (CA3), cert. denied, 426 U.S. 935 (1976); Contreras v. Grower Shipper Vegetable Assn., 484 F.2d 1346 (CA9 1973), cert. denied, 415 U.S. 932 (1974); Reibert v. Atlantic Richfield Co., 471 F.2d 727 (CA10), cert. denied, 411 U.S. 938 (1973). But see Nichols v. Spencer Int'l Press, Inc., 371 F.2d 332, 334 (CA7 1967).

Indeed, if there is substance to the Union's claim, it is difficult to understand why these direct victims of the conspiracy have not asserted any claim in their own right. The Union's suggested explanations of this fact tend to shed doubt on the proposition that these "victims" were actually harmed at all.
"Many unionized firms will respond to the alleged boycott . . . by setting up double-breasted operations or shifting more of their resources to the non-unionized part of their operations when double-breasted operations already exist. In this manner, unionized subcontractors can avoid losing any business and, as a result, these subcontractors will not `possess the classic economic incentive to file suit.' Alternatively, unionized subcontractors may simply not renew the collective bargaining agreement when it expires." Brief for Respondents 49 (citation omitted).

Cf. Blue Chip Stamps v. Manor Drug Stores, 421 U.S. 723, 739-748 (1975) (purchaser-seller limitation on actions under § 10(b) of Securities Exchange Act of 1934).

We expressly noted in McCready:
"[O]ur cautious approach to speculative, abstract, or impractical damages theories has no application to McCready's suit. The nature of her injury is easily stated: As the result of an unlawful boycott, Blue Shield failed to pay the cost she incurred for the services of a psychologist. Her damages were fixed by the plan contract and, as the Court of Appeals observed, they could be `ascertained to the penny.'" 457 U.S., at 475-476, n. 11.

This interest was also identified in the legislative debates preceding the enactment of the Sherman Act. Speaking in opposition to a proposed amendment that might have complicated the procedures in private actions, Senator Edmunds said:
"Therefore I say as to the suggested amendment of my friend from Mississippi — and I repeat it in all earnestness — that if I were a lobbyist and wanted to entangle this business, I should provide that everybody might sue everybody else in one common suit and have a regular potpourri of the affair, as his amendment proposes, and leave it to the lawyers of the trust to have an interminable litigation in respect of the proper parties, whether their interests were common or diverse or how they were affected, and take twenty years in order to get a result as to a single one of them. The Judiciary Committee did not think it wise to do that sort of thing, because we were in earnest about the business, as I know my friend is." 21 Cong. Rec. 3148 (1890).
See also id., at 3149 (remarks of Senator Morgan opposing same amendment: "There is as much harm in trying to do too much as there is in not trying to do anything, and I think we have stopped at about the proper line in this bill, and I shall support it just as it is").

We pointed out in McCready, 457 U.S., at 475, n. 11:
"If there is a subordinate theme to our opinions in Hawaii and Illinois Brick, it is that the feasibility and consequences of implementing particular damages theories may, in certain limited circumstances, be considered in determining who is entitled to prosecute an action brought under § 4. . . . Thus we recognized that the task of disentangling overlapping damages claims is not lightly to be imposed upon potential antitrust litigants, or upon the judicial system."

Although the policy against duplicative recoveries may not apply to the other type of harm asserted in the Union's brief — reduction in its ability to persuade nonunion contractors to enter into union agreements — the remote and obviously speculative character of that harm is plainly sufficient to place it beyond the reach of § 4. See n. 46, supra.