New Evidence Suggests Widespread Insider Trading in Military Markets on Polymarket

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. The findings indicate 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 reaching over 50%.

This is in stark contrast to the typical 14% success rate for longshot bets in political markets. The authors suggest that markets tied to government policies, such as military and defense, are more susceptible to information asymmetries, including insider trading or specialized knowledge.

The gap between informed and uninformed traders may be widest in these markets, allowing a small group to consistently outperform others. The report's findings add to existing research, which shows that roughly 3% of traders account for most price discovery on Polymarket, and fewer than 1% of wallets capture about half of all gains.

The ACDC 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 pattern of well-timed bets on military and defense outcomes extends beyond this single event, with winning longshot bets outnumbering losing ones in five of the six two-hour windows before market resolution. While longshot bets can outperform due to various reasons, the consistency of the patterns suggests that some participants may have 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 on whether the public should be betting on these outcomes at all.