These C.E.O.s Loathe Each Other? Bet on It.

Competition in prediction markets between Polymarket and Kalshi has turned into a high-stakes legal and regulatory confrontation involving the U.S. federal government. In early November 2024, Polymarket founder Shayne Coplan said FBI agents raided his New York apartment with a battering ram while searching for evidence of illegal betting on the platform. Coplan publicly dismissed the raid as politically motivated, but privately he and advisers pointed to Tarek Mansour, CEO of Kalshi, a major rival. The article cites people familiar with discussions indicating that Kalshi’s lawyers met Manhattan federal prosecutors before the raid, raising concerns about Polymarket and arguing that U.S. customers could use it despite being “supposedly” banned. The wider feud includes competing trademark filings, disputes over deals and talent, press clashes, and name-calling.