House Oversight Committee opens insider-trading investigation into Kalshi and Polymarket

Friday, May 22, 2026Business & MarketsWell-covered3 frames

The House Oversight Committee opened an investigation into alleged insider trading on prediction-market platforms Kalshi and Polymarket.
House Oversight Chairman James Comer sent letters to Kalshi CEO Tarek Mansour and Polymarket CEO Shayne Coplan requesting documents and information from the companies.
Comer asked for information on how the platforms verify user identities, enforce geographic restrictions or block offshore access, and monitor or flag suspicious trading activity.
The investigation is focused on whether users may have used nonpublic or classified information to profit from trades on the platforms.
The congressional inquiry follows scrutiny over suspiciously timed trades tied to geopolitical or military events, including bets related to Venezuela and Iran.
The probe matters beyond the two companies because lawmakers are weighing whether prediction markets need tighter federal oversight or new legislation, including concerns about government officials or members of Congress using privileged information.
What remains unresolved is whether internal company records will show failures in compliance controls or evidence of improper trading, and what actions Congress may take after reviewing the requested materials.

How left and right are reading this

Both agree: Possible profit from nonpublic or classified information is the core concern, and the probe’s requests on identity checks, geographic restrictions, and suspicious-activity monitoring are meant to test whether Kalshi and Polymarket had credible safeguards against that abuse.
They split on: Less a disagreement than a question of emphasis: whether the probe chiefly highlights a fairness problem when privileged knowledge distorts who benefits, or the need to wait for the records before judging compliance failures and deciding on new federal oversight.

The House Oversight Committee opened an investigation into alleged insider trading on prediction-market platforms Kalshi and Polymarket.
House Oversight Chairman James Comer sent letters to Kalshi CEO Tarek Mansour and Polymarket CEO Shayne Coplan requesting documents and information from the companies.
Comer asked for information on how the platforms verify user identities, enforce geographic restrictions or block offshore access, and monitor or flag suspicious trading activity.
The investigation is focused on whether users may have used nonpublic or classified information to profit from trades on the platforms.
The congressional inquiry follows scrutiny over suspiciously timed trades tied to geopolitical or military events, including bets related to Venezuela and Iran.
The probe matters beyond the two companies because lawmakers are weighing whether prediction markets need tighter federal oversight or new legislation, including concerns about government officials or members of Congress using privileged information.
What remains unresolved is whether internal company records will show failures in compliance controls or evidence of improper trading, and what actions Congress may take after reviewing the requested materials.