General introduction to the legislative framework for private antitrust enforcement
Private plaintiffs may bring suit in federal court for violations of federal antitrust law under two provisions of the Clayton Act of 1914. Section 4 allows private plaintiffs to sue for money damages, including reasonable attorneys' fees as well as prejudgment interest on actual damages at a court's discretion if such an award is just under the circumstances. Section 16 allows private plaintiffs to sue for injunctive relief.i Statute of limitations limit the period of potential recovery
A four-year statute of limitations applies to Section 4 claims. The limitations period commences when the cause of action accrues, which generally occurs when the plaintiff suffers injury and damages become ascertainable. Section 16 claims may also be subject to a four-year statute of limitations. Some courts have held that the four-year limitation period also applies to Section 16 claims, while others have held that it does not. The defence of laches nevertheless bars Section 16 claims four years after accrual of the cause of action, unless the court finds equitable reasons to allow the claim.
The statute of limitations may be tolled by government antitrust actions, the filing of a class action, fraudulent concealment, duress or equitable estoppel. Where a series of overt acts rather than one definitive act causes new injury to plaintiffs, the continuing violation doctrine restarts the statute of limitations period. Some courts allow the tacking of tolling periods.ii State antitrust claims
Most US states and territories have adopted antitrust statutes. They generally mirror the federal scheme, and prohibit monopolies and unreasonable agreements (like the Sherman and Clayton Acts) and unfair and deceptive trade practices (like the Federal Trade Commission (FTC) Act). The vast majority provide for private rights of action. Statute of limitations periods vary by state.
The statutes and courts' interpretations of them differ on various points, such as the availability of treble damages, restitution, class actions and availability of recovery for indirect purchasers.