House Oversight Committee Opens Probe Into Prediction Market Insider Trading

The House Oversight Committee announced Friday that it has opened an investigation into prediction-market operators Kalshi and Polymarket over possible insider trading. Committee chairman Rep. James Comer sent letters to Kalshi CEO Tarek Mansour and Polymarket CEO Shayne Coplan asking for records on how each platform detects and prevents trading on non-public information.

The letters seek details on internal investigation procedures and on identity-verification steps used for both U.S. and foreign account holders. Lawmakers cited recent trading activity tied to developments in the Iran conflict and to the Trump administration's detention of former Venezuelan leader Nicolás Maduro.

A data-analytics review reported by "60 Minutes" found that nine Polymarket accounts earned a combined $2.4 million by correctly forecasting key dates in the Iran conflict. In April, federal prosecutors charged a U.S. special forces soldier with using confidential government information to place bets on Maduro's removal, a position that reportedly returned more than $400,000.

The soldier, identified as Gannon Ken Van Dyke, 38, faces charges including unlawful use of confidential government information, commodities fraud and wire fraud; he has pleaded not guilty.

" Kalshi spokesperson Elisabeth Diana said the company has put in place "comprehensive" safeguards and recently fined three congressional candidates, suspending their accounts for five years after finding they had traded on their own races. Kalshi now bars members of Congress from opening accounts, while Polymarket adopted a March rule prohibiting traders who "hold a position of authority" from betting on events they could influence.