Senate bans members, staff from prediction markets

The U.S. Senate voted unanimously Thursday to bar senators and Senate staff from using prediction markets, changing the chamber’s standing rules by unanimous consent and putting the ban into immediate effect. Republican Senator Bernie Moreno introduced the resolution on the Senate floor.

Lawmakers said the change responds to recent allegations that sensitive or classified information could be used to profit on event-betting platforms. They pointed to a federal charge filed April 23 accusing a special forces service member of using classified material to place wagers on Polymarket; the defendant has pleaded not guilty. Senators also referenced questions about well-timed bets linked to the conflict with Iran.

Moreno told colleagues that engaging with prediction markets when holding private information undermines public trust. “Engaging in any way in a prediction market or trying to place bets where we might have inside information deteriorates the confidence that our constituents have in us,” he said, and added that the rule makes clear no senator or Senate staffer can use inside information to monetize the job.

Senate Democratic leader Chuck Schumer supported the ban, calling the vote a “no-brainer” and saying members should not be able to “gamble on wars, or economic crises, or elections.” He urged that similar restrictions be applied across the executive branch.

Republican Representative Ashley Hinson said she will introduce a companion resolution in the House to extend the prohibition to House members and staff. The Senate action changes only the chamber’s internal rules; a broader federal ban would require separate legislation or House approval.

Prediction market companies posted support for the Senate action. Polymarket said it backs the resolution and noted its terms of service already prohibit trading on insider information. Tarek Mansour, co-founder and CEO of rival platform Kalshi, wrote that his company blocks members of Congress from using its service and enforces rules against insider trading.

Prediction markets let participants place bets on outcomes such as elections, policy decisions and international events, with prices reflecting market expectations. Lawmakers said members and staff sometimes have access to classified, nonpublic or sensitive information that could affect those markets or create the appearance of profiting from public office.

The resolution applies only to Senate members and employees and took effect immediately under the unanimous consent agreement. If the House and the executive branch adopt similar bans, members of Congress and federal officials would face uniform restrictions on engaging with these platforms.