Report: Polymarket may have a broader insider trading issue, with a few wallets capturing most of the profits

The latest report from the non-profit research organization Anti-Corruption Data Collective (ACDC) indicates that the prediction market platform Polymarket may have broader insider trading issues than the previously reported "Green Beret Bet on the Venezuela Raid."

The research analyzed 435,000 settled markets from January 2021 to mid-March 2026, with a total trading volume of $54.4 billion, and found that low-probability bets related to government decision-making in military and defense markets had abnormally high success rates. Data shows that the average success rate for such "long-shot bets" in political markets is about 14%, while in some cases of military-related contracts, the success rate exceeds 50%. The study suggests that these markets are difficult to predict based solely on public information and are more susceptible to information asymmetry, including insider trading or professional information advantages.

The report also points out that Polymarket's profits are highly concentrated. Research from the London Business School and Yale University shows that about 3% of traders contribute to most of the platform's price discovery; blockchain analytics firm Solidus Labs found that less than 1% of wallets accounted for about half of the profits. For example, in the case of the U.S. airstrike on Iran in June 2025, just hours before the attack, 19 low-probability bets totaling $164,000 concentrated on buying the ultimately realized "YES" contract, with 8 wallets collectively profiting about $1.8 million, including one wallet that made nearly $500,000.

Despite the Pentagon's efforts to conceal the operation through decoy bombers and stealth fighters, a few traders accurately predicted the outcome. ACDC recommends that Polymarket strengthen identity verification, set conditional payments for suspicious bets, limit markets where results are determined by a few individuals, and reduce overly detailed contract designs. The report further calls for a broader discussion on whether the public should be allowed to bet on such events.