The Washington State Securities Act includes the following provision:

"Any condition, stipulation, or provision binding any person acquiring any security to waive compliance with any provision of this chapter or any rule or order hereunder is void."

Wash. Rev. Code § 21.20.430(5).  Similar provisions can be found in the Uniform Securities Act and in the California Corporate Securities Law of 1968 (Cal. Corp. Code § 25701). 

In Sun v. Advanced China Healthcare, Inc., 2018 U.S. App. LEXIS 23587, the plaintiffs had filed a lawsuit in Washington district court alleging violations of the WSSA despite the fact that they had agreed that any disputes "arising out of or related to" their share purchase agreements be adjudicated in California state court.  The district court dismissed the action and the plaintiffs appealed, arguing that the forum selection agreement was unenforceable in light of Washington's antiwaiver statute.

The Ninth Circuit Court of Appeals found that the WSSA's antiwaiver statute does not per se preclude enforcement of a forum selection clause.  Instead, the Court of Appeals found that the plaintiffs must point to either a statute or judicial decision that clearly enunciates a strong public policy of the State of Washington.  Although the plaintiffs tried, the Court of Appeals found their efforts wanting and affirmed the dismissal.