The Senate voted unanimously to bar senators, their staff and other chamber officials from participating in prediction markets, where users wager on the outcomes of future events, including major government decisions. Lawmakers said the move was necessary to prevent conflicts of interest and protect national security.

The ban followed reports that several accounts earned hundreds of thousands of dollars by correctly predicting recent United States military actions. At least 16 accounts reportedly profited more than 100,000 dollars after forecasting a February strike on Iran shortly before it occurred. The activity raised concerns that insider information could be exploited for financial gain.

Senator Elissa Slotkin of Michigan, a former analyst with the Central Intelligence Agency, warned that such betting could pose operational risks. Senator Bernie Moreno of Ohio, who sponsored the measure, said public service should not be used for personal profit. Senate Democratic leader Chuck Schumer urged the House of Representatives to adopt a similar prohibition.

Some lawmakers are now pushing to expand the ban to cover all federal officials, including the president and vice president, with financial penalties for violations. Prediction market companies have said they are strengthening safeguards, though recent cases involving political candidates and a military service member have intensified scrutiny.