The U.S. House Oversight Committee is investigating prediction market platforms Polymarket and Kalshi over concerns that government employees may be using classified information for personal gain.
Rep. James Comer, R-Ky., chair of the House Oversight and Government Reform Committee, told CNBC's Squawk Box on Friday that he has sent letters to Polymarket CEO Shayne Coplan and Kalshi CEO Tarek Mansour demanding internal records. The probe aims to determine whether members of Congress, administration officials, or other government employees are using insider knowledge to profit from policy, geopolitical, and military operations.
Comer is seeking clarity on how the platforms handle identity verification, enforce geographic restrictions, and flag anomalous trading activity. The letters come amid broader congressional scrutiny following a heated Senate Commerce Committee hearing this week where lawmakers from both parties criticized prediction markets for enabling cheating in sports and fostering problem gambling.
The prediction market sector has surged in popularity, with volumes hitting $51 billion last year and projected to reach roughly $240 billion in 2026. A Bernstein report forecasts volumes could peak at $1 trillion by 2030 as the sector evolves into broad-based information markets spanning sports, crypto, politics, and the economy.
Nicolas Vaiman, co-founder of onchain intelligence firm Bubblemaps, warned that irregular trades visible on these platforms pose a national security risk, as adversaries could exploit the same signals. His team identified 80 bets on Polymarket with a 98% win rate, which he called statistically impossible.