ACDC Report: Polymarket Shows Widespread Insider Trading; Less Than 1% of Wallets Capture Half of Profits

According to a report by Anti-Corruption Data Collective (ACDC) released in mid-March 2026, Polymarket may have broader insider trading issues than previously known. Analysis of 435,000 settled markets and $54.4 billion in trading volume from January 2021 to mid-March 2026 reveals unusually high success rates for low-probability bets in military and defense-related markets, with some military contracts showing success rates exceeding 50% compared to an average of 14% for political markets.

Polymarket profits are highly concentrated, with less than 1% of wallets capturing approximately half of all profits. In a June 2025 case involving a U.S. airstrike on Iran, 19 bets totaling $164,000 were placed hours before the strike, with 8 wallets collectively profiting around $1.8 million, including one wallet earning close to $500,000.