Professor Ronald Colombo joined other securities law experts, including former SEC officials, in signing an amicus brief on behalf of Volkwagen AG before the United States Court of Appeals for the Ninth Circuit (see In re: Volkswagen “Clean Diesel” Marketing,Sales Practices, and Prods. Liab. Litig., No. 20-80026 (9th Cir. 2020)). The brief argues that the district court improperly extended the private right of action for securities fraud actions brought under Section 10(b) of the Securities Exchange Act beyond the boundaries established by the U.S. Supreme Court.