“No Gambling Act” sign speaks during a press conference at the U.S. Capitol on Tuesday, March 17, 2026, in Washington, DC, U.S. Representative Greg Cassar, a Democrat from Texas, left, and Sen. Chris Murphy, a Democrat from Connecticut.
Stephanie Reynolds | Bloomberg | Getty Images
The U.S. Senate on Thursday unanimously passed a rule banning senators from trading in prediction markets, effective immediately.
The move comes amid growing concerns about insider trading on prediction market platforms such as Calci and Polymarket, as well as event contracts that can involve death or violence.
On April 22, Carsi announced that he had suspended and fined one U.S. Senate candidate and two U.S. House candidates for alleged political insider trading in his campaign.
On April 23, U.S. Army Special Forces soldier Sgt. Gannon Ken Van Dyke was arrested and charged with disseminating classified information to bet on polymarkets in connection with the US military mission that captured Venezuelan leader Nicolás Maduro.
Van Dyke, who was on the mission, won nearly $410,000 on those bets, according to the Justice Department.
Earlier Thursday, a group of Democratic lawmakers called on the Commodity Futures Trading Commission to enact rules to “prevent insider trading and corruption in the markets and prohibit event contracts for the outcome of elections, wars or military actions within or outside the United States, sports, or government activities without effective economic hedging rights.”
Both Carsi and Polimarquette praised the Senate’s actions.
“We applaud the Senate for passing this resolution that prohibits senators and their offices from trading in prediction markets,” Karsi CEO Tarek Mansour said in a post about X.
“Kalsi is already actively blocking members of Congress and cracking down on insider trading. Making this an industry standard is a great step to increase confidence in the market,” Mansour said. “Now, let’s pass this in Congress!”
In its own post about X, Polymarket said: “We fully support this. Our rulebook and terms of service already prohibit such behavior, but codifying this into law is a step forward for the industry. We are happy to support this push in any way we can.”
Disclosure: CNBC and Kalsi have a commercial relationship that includes a minority investment in CNBC.
