Credit Suisse Securities (USA) LLC v. Simmonds, 566 U.S. 221 (2012), is a United States Supreme Court decision regarding the limitation period for insider trading claims.

[1][2] The court ruled in an 8-0 unanimous opinion that the limitation period was subject to traditional equitable tolling.

In 2007, Vanessa Simmonds, a recent college graduate, simultaneously filed lawsuits against eleven investment banks involving fifty-five initial public offerings accusing them of abuses during the internet firm IPOs from 1999 to 2001 that eventually led to the dot com bust.

[3] Amongst her lawyers was her father David Simmonds who had earlier successfully argued a similar case against an internet start-up resulting in the largest judgment and recovery to date under Section 16(b) of the Security Exchange Act of 1934.

A federal district court consolidated the nearly identical cases and granted a motion to dismiss, stating that the two year limitation on the period on Section 16(b) had expired.