28 U.S.C. § 1658

1. (a)Except as otherwise provided by law, a civil action arising under an Act of Congress enacted after the date of the enactment of this section may not be commenced later than 4 years after the cause of action accrues.
2. (b)Notwithstanding subsection (a), a private right of action that involves a claim of fraud, deceit, manipulation, or contrivance in contravention of a regulatory requirement concerning the securities laws, as defined in section 3(a)(47) of the Securities Exchange Act of 1934 (15 U.S.C. 78c(a)(47)), may be brought not later than the earlier of—
   1. (1)2 years after the discovery of the facts constituting the violation; or
   2. (2)5 years after such violation.