"Bets Off Act" signage as Representative Greg Casar, a Democrat from Texas, left, and Senator Chris Murphy, a Democrat from Connecticut, speak during a news conference at the US Capitol in Washington, DC, US, on Tuesday, March 17, 2026. Stefani Reynolds | Bloomberg | Getty Images The U.S. Senate on Thursday unanimously passed a rule barring senators from trading on prediction markets effective immediately. The move came amid rising concern about insider trading on prediction market platforms such as Kalshi and Polymarket , and about event contracts that can involve death or violence. On April 22, Kalshi said it had suspended and fined one U.S. Senate candidate and two candidates for the House of Representatives for political insider trading on their own campaigns. On April 23, a U.S. Army Special Forces soldier, Master Sgt.…