The alleged insider trading by a Green Beret, who placed a $400,000 bet on a raid in Venezuela, may be just the tip of the iceberg. A recent report by the Anti-Corruption Data Collective, a nonprofit research group, analyzed over 435,000 markets and $54.4 billion in cumulative volume on Polymarket from January 2021 to mid-March 2026. The findings suggest that low-probability bets on military and defense outcomes have success rates that are difficult to explain by skill or luck alone, with some cases seeing success rates above 50%.

This is significantly higher than the 14% success rate typically seen in political markets. The report's authors note that markets related to government policies, such as military and defense, are harder to forecast using public information, making them more susceptible to insider trading or specialized knowledge. The gap between informed and uninformed traders may be widest in these markets, creating an environment where a small group can consistently outperform others.

The report's findings add to existing research, which suggests that roughly 3% of traders account for most price discovery on Polymarket, and that profits are highly concentrated, with fewer than 1% of wallets capturing about half of all gains. The report examines the June 2025 U.S. strikes on Iran as a case study, where 19 longshot bets totaling $164,292 were placed in the hours leading up to the strike, resulting in profits of about $1.8 million for eight wallets. The Pentagon's use of decoy bombers and stealth aircraft to avoid detection did not prevent a small number of traders from placing well-timed bets on the outcome.

The report found that in five of the six two-hour windows before market resolution, winning longshot bets outnumbered losing ones, contrary to what market prices imply. While longshot bets can outperform due to mispricing or shifts in public expectations, the consistency of the patterns suggests that some participants may be operating with information advantages.

The report recommends identity verification for bettors, conditional payouts on suspicious wagers, restrictions on markets whose outcomes are decided by small groups, and limits on contract granularity. Ultimately, the report calls for an evidence-informed debate about whether the public should be betting on these outcomes at all.