The alleged insider trading incident involving a Green Beret's $400,000 bet on a Venezuelan raid may be just the tip of the iceberg. A new report by the Anti-Corruption Data Collective (ACDC) analyzed over 435,000 Polymarket contracts and $54.4 billion in cumulative volume from January 2021 to mid-March 2026, revealing that low-probability bets on military and defense outcomes have won at rates that cannot be explained by skill or luck alone.
In some cases, success rates have exceeded 50%, significantly higher than the typical 14% success rate for longshot bets across political markets. The report suggests that markets related to government policies, such as military and defense, are more susceptible to information asymmetries, including insider trading or specialized knowledge, due to the difficulty in forecasting outcomes using public information alone.
This creates an environment where a small group of informed traders can consistently outperform others, not just by reacting faster, but by possessing more knowledge. The study also found that in the hours leading up to the June 2025 U.S. strikes on Iran, 19 longshot bets totaling $164,292 were placed across contracts that ultimately resolved YES, with eight wallets sharing about $1.8 million in profits. The report's findings add to existing research indicating that roughly 3% of traders account for most price discovery on Polymarket, with fewer than 1% of wallets capturing about half of all gains.
To address these concerns, the ACDC recommends implementing identity verification for bettors, conditional payouts on suspicious wagers, restrictions on markets whose outcomes are decided by small groups, and limits on how granular contracts can become. Ultimately, the report calls for an evidence-informed debate on whether the public should be allowed to bet on these outcomes at all.