Senate bans members, staff from prediction-market bets

The Senate on Thursday unanimously adopted a standing rule that bars senators, staff and chamber officers from placing wagers on event-based prediction markets. The change to the chamber’s rules took effect immediately after passage by unanimous consent.

Lawmakers acted after federal prosecutors indicted Army Special Forces Master Sergeant Gannon Ken Van Dyke on charges that he used classified information to place wagers on Polymarket. Prosecutors allege Van Dyke made about $33,034 in 13 bets tied to an operation and won roughly $409,881; he pleaded not guilty and was released on $250,000 bail. The Commodity Futures Trading Commission filed a parallel civil complaint and described the matter as its first insider trading action involving prediction markets.

Senate Resolution 708 was introduced by Republican Senator Bernie Moreno and expanded by Democratic Senator Alex Padilla to cover Senate staff. Moreno said, “United States senators have no business engaging in speculative activities like prediction markets while collecting a taxpayer-funded paycheck.” Senate Democratic Leader Chuck Schumer warned against letting public office become a venue for betting on wars or economic crises.

The rule is internal to the Senate and will be enforced through the chamber’s ethics process. Possible sanctions include reprimands, loss of committee assignments and fines tied to ethics violations. The rule does not create new criminal penalties; federal prosecutors and regulators retain authority to pursue violations of outside laws.

Regulators and academics have highlighted vulnerabilities in prediction markets. David Miller, director of enforcement at the CFTC, named insider trading on prediction markets as an agency enforcement priority and said the idea that insider trading is acceptable in those markets is a myth. Researchers at Columbia Law School and the University of Haifa reviewed Polymarket activity through February 2026 and flagged more than 210,000 suspicious wallet-market pairs, finding flagged traders posted about a 70% win rate and amassed an estimated $143 million in anomalous profit.

Polymarket has tightened its insider trading rules on both its decentralized platform and its U.S. exchange. Separate bills from Senators Todd Young and Elissa Slotkin would bar federally elected officials and government employees from using insider information in prediction markets; Young described the Senate resolution as a positive initial measure.

Prediction markets are treated differently across jurisdictions: some regulators treat certain contracts as financial derivatives, while others classify them as gambling. Legal observers say a conviction in the Van Dyke case would clarify how federal commodity rules apply when classified government information is used in trading.