House Oversight Chair James Comer Demands Answers from Kalshi and Polymarket Over Insider Trading Concerns

James Comer, Chairman of the House Oversight Committee, has formally requested information from the CEOs of prediction market platforms Kalshi and Polymarket amid growing concerns over alleged insider trading activity on their platforms.

According to reports, Comer sent letters on Friday to Shayne Coplan and Tarek Mansour, demanding records and information related to how the companies monitor suspicious trading activity and comply with legal obligations.

The letters, obtained by CNBC, signal increasing congressional attention toward the rapidly growing prediction market industry, which allows users to trade on the outcomes of political, economic, and real-world events.

Concerns Over Transparency and Market Integrity

In his communication to Polymarket, Comer emphasized that internal company records may be critical in identifying potential misconduct and determining whether the platforms are adequately enforcing compliance measures.

“Internal records are the only means by which bad actors can be identified and to determine whether platforms are meeting their legal obligations,” Comer wrote.

The statement reflects broader concerns surrounding transparency, oversight, and market integrity within prediction markets—particularly as these platforms continue attracting larger volumes of users and capital.

Prediction Markets Under Growing Scrutiny

Prediction markets have gained significant popularity in recent years by allowing participants to place trades tied to the probability of future events, ranging from elections and legislation to financial and global developments.

Supporters argue that such platforms can aggregate public information efficiently and provide insights into market sentiment. Critics, however, warn that the systems may be vulnerable to manipulation, misuse of non-public information, and insufficient regulatory safeguards.

The allegations referenced by Comer suggest fears that individuals with privileged information could potentially exploit these markets for financial gain before information becomes publicly available.

Regulatory Questions Intensify

The requests for information from Kalshi and Polymarket come at a time when regulators and lawmakers are increasingly evaluating how prediction markets should operate within existing legal and financial frameworks.

Questions surrounding compliance, user monitoring, and enforcement standards have become more pressing as the industry expands and intersects with political forecasting, economic speculation, and emerging digital financial ecosystems.

The Oversight Committee’s inquiry could potentially lead to broader discussions about federal oversight, reporting requirements, and the responsibilities of prediction market operators in preventing market abuse.

A Defining Moment for the Industry

For both Kalshi and Polymarket, the congressional scrutiny represents a significant moment in the evolution of the prediction market sector. The outcome of the inquiry may influence how these platforms are regulated and perceived moving forward.

As lawmakers seek greater transparency into trading activity and internal compliance practices, the broader industry faces increasing pressure to demonstrate accountability, safeguard market integrity, and build trust among users and regulators alike.