Senators question Kalshi, Polymarket over election betting manipulation and insider trading risks

US Senators Elizabeth Warren and John Curtis have raised concerns over potential insider trading and market manipulation on election-related prediction markets , questioning whether operators Kalshi and Polymarket can adequately detect and prevent improper trading. In a bipartisan letter to Kalshi CEO Tarek Mansour and Polymarket CEO Shayne Coplan, the lawmakers demanded details of existing safeguards, previous enforcement actions, and suspected violations referred to the Commodity Futures Trading Commission's ( CFTC ) rules.