Shortly after facing scrutiny from Congress in the GameStop trading saga, Citadel Securities announced Thursday that the former head of the U.S. Commodity Futures Trading Commission (CFTC) will serve as the company’s chief legal officer.

Heath Tarbert will begin his role April 5 and will be based in the company’s Chicago headquarters. Tarbert replaces Steve Luparello as the investment firm’s top lawyer. Luparello joined the company in 2017 after leaving the Securities and Exchange Commission as its director of trading and markets. A spokesperson said Luparello will continue to serve as an adviser to the firm through the end of the year, at which point he plans on retiring.