The U.S. House Speaker launched a congressional investigation into Kalshi and Polymarket for alleged insider trading.

CoinFeed reported on May 22 that, according to CNBC, James Comer, chairman of the U.S. House Oversight and Reform Committee, launched an investigation into prediction market platforms Kalshi and Polymarket, sending letters to the CEOs of both companies requesting internal documents on measures to prevent insider trading, identity verification, geographic restrictions, and monitoring of unusual transactions. Comer stated that internal records are the only way to identify accounts suspected of profiting from national security secrets (including military personnel and those with security clearances). The investigation focuses on transactions related to election results, U.S. military actions against Iran, and Venezuela. Previously, a U.S. soldier was arrested for profiting approximately $400,000 from Polymarket using intelligence related to regime change in Venezuela, and more than 80 users were reported to have placed orders hours before the U.S.-Israeli airstrikes on Iran.