The limitation period for any private civil action implied under section 78j(b) of this title that was commenced on or before June 19, 1991, shall be the limitation period provided by the laws applicable in the jurisdiction, including principles of retroactivity, as such laws existed on June 19, 1991.
15 U.S. Code § 78aa–1. Special provision relating to statute of limitations on private causes of action
For information regarding constitutionality of certain provisions of section 27A of act June 6, 1934, as added by section 476 of Pub. L. 102–242, see Congressional Research Service, The Constitution of the United States of America: Analysis and Interpretation, Appendix 1, Acts of Congress Held Unconstitutional in Whole or in Part by the Supreme Court of the United States.