U.S. House Committee Probes Polymarket and Kalshi Over Suspected Insider Trading

The U.S. House Committee on Oversight and Government Reform has launched an investigation into prediction markets Polymarket and Kalshi amid allegations of insider trading. Committee Chair James Comer emphasized that internal records from these platforms are critical for assessing compliance and identifying potential misuse of nonpublic government data.

Suspicious trading incidents under scrutiny include a U.S. Army sergeant allegedly profiting $409,000 on Polymarket using classified information. Kalshi recently banned three congressional candidates—Mark Moran, Matt Klein, and Ezekiel Enriquez—for betting on their own races, imposing 5-year bans and fines. While this demonstrates self-regulatory capabilities, the committee demands further documentation on user verification, geographic restrictions, and surveillance systems.

Formal information requests have been sent to Polymarket CEO Shayne Coplan and Kalshi CEO Tarek Mansour. The probe underscores growing regulatory attention on prediction markets and their vulnerability to exploitation.