The Tennessee regulatory authorities in the United States have taken enforcement actions against sports event prediction trading platforms. Kalshi, Polymarket, and other three platforms were required to make immediate rectifications for operating without a license within the state, violating state gambling laws. According to the regulatory order, the relevant platforms must fully cease providing sports event contract trading services to users in the state by January 31 and fully refund user deposits and margins. Failure to comply by the deadline will result in hefty fines. This move reflects the increasingly strict regulatory attitude of U.S. states towards on-chain derivatives trading platforms. Platform operators need to strengthen compliance assessments of regulatory frameworks across different regions, especially regarding the legality certification of their operations in the domestic U.S. market.