House Oversight Committee Chairman James Comer launched an investigation into Kalshi and Polymarket, examining potential insider trading on prediction-market platforms. The Republican-led probe seeks to determine how users might exploit non-public information to influence market outcomes, raising questions about regulatory oversight in this emerging financial sector that has attracted significant capital.

Comer sent letters to both platform CEOs requesting documentation on identity verification procedures, geographic restriction enforcement, and monitoring of suspicious trading activity. The investigation comes as prediction markets gain popularity but face increasing scrutiny about potential manipulation and compliance with securities regulations governing similar financial instruments.

This congressional oversight could significantly impact how prediction-market platforms operate, potentially requiring stricter compliance measures. The investigation signals growing regulatory attention toward these emerging financial instruments, which allow traders to bet on political and economic events, raising concerns about market integrity and investor protection in this rapidly evolving sector.