Senate bars members and staff from prediction-market trading

The U.S. Senate voted unanimously Thursday to change chamber rules and ban senators and their staff from taking part in online prediction markets. The resolution was sponsored by Republican Senator Bernie Moreno of Ohio and will be enforced by the Senate itself. The change does not create a federal crime and does not require approval by the House or the president.

Moreno wrote on X that “Serving in Congress is an honor, not a side hustle,” adding that Americans deserve assurance their leaders act for the right reasons.

The rule change follows increased scrutiny of prediction markets after a recent criminal charge. Federal prosecutors last week accused U.S. Army Special Forces Master Sergeant Gannon Ken Van Dyke of using advance knowledge of the ouster of Venezuelan President Nicolás Maduro to place profitable bets on Polymarket. A separate civil complaint from the Commodity Futures Trading Commission alleges those trades produced more than $404,000 in illicit gains. Prosecutors say Van Dyke was involved in planning and executing the operation tied to Maduro’s removal.

Congressional activity this year reflects broader interest in stricter limits. Representative Ritchie Torres introduced the Public Integrity in Financial Prediction Markets Act of 2026 in January to bar federal officials from trading on these platforms. In March, Senators Jeff Merkley and Amy Klobuchar proposed legislation to prohibit senior executive-branch officials from participating. Representatives Blake Moore and Salud Carbajal proposed a bipartisan bill aimed at insider trading linked to sensitive military information and electoral processes. Other proposals would restrict markets that reference sports betting or offer wagers tied to terrorism, assassination, war or an individual’s death.

State and private institutions have issued restrictions as well. Illinois Governor J.B. Pritzker prohibited state employees from using insider information to place bets on prediction markets.

Senator Richard Blumenthal has accused Polymarket of allowing users to profit from national security secrets and criticized the platform for opening a market that referenced the rescue of a U.S. soldier in Iran.

Polymarket’s deputy chief legal officer, Olivia Chalos, wrote on X that the company operates in full compliance with applicable law and that its insider-trading rules follow CFTC guidance and court precedents. She added the platform shares concerns about national security and market integrity.

The new Senate rule aims to prevent conflicts of interest within Congress but does not set new criminal penalties or federal regulatory standards. Enforcement will depend on the chamber’s internal procedures. Lawmakers continue to consider statutory options that would establish clearer legal restrictions and oversight for prediction markets nationwide.