This case concerned whether the filing of a class action complaint tolls the running of the three-year “repose” period in 15 U.S.C. § 77m applicable to Securities Act claims for all members of the proposed class. The Supreme Court held long ago in a case called American Pipe v. Utah that the filing of a class-action complaint generally stops the running of the statute of limitations for all class members, even if the class is not ultimately certified or class members opt out. In this case, however, the defendants argued that this principle should not apply to the “repose” period established by limitations periods applicable to federal securities claims. The U.S. Court of Appeals for the Second Circuit agreed, and the Supreme Court granted the plaintiffs’ petition for certiorari. Public Citizen filed an amicus brief supporting the plaintiffs, arguing that application of the American Pipe rule to the “repose” period does not affect substantive rights in violation of the Rules Enabling Act and that not applying American Pipe would violate due process by impairing opt-out rights of class members. The Court, however, held that the repose period is not subject to equitable tolling.