The top Republican on the House Committee on Oversight and Government Reform announced Friday that the panel is launching an investigation into prediction market companies Kalshi and Polymarket over allegations of insider trading and exploiting regulatory loopholes.

Rep. James Comer (R-KY) said lawmakers are examining the “adequacy of company safeguards to prevent access to offshore sites to circumvent compliance with applicable U.S. federal regulations governing prediction market platforms,” in a Friday letter sent to Kalshi CEO Tarek Mansour.