Polymarket's investigations team scrutinized "dozens" of bets on U.S. midterm election markets for signs of possible insider trading, with at least two cases escalated to the Commodity Futures Trading Commission (CFTC), according to NPR reporting. The probe focused on suspicious trading patterns in prediction market contracts tied to control of the House of Representatives, a market that attracted nearly $24 million in cumulative volume ahead of the midterms. Polymarket's head of investigations confirmed the internal review and subsequent referrals to federal regulators.