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, uncovering unusually high win rates for low-probability bets on military and defense outcomes. These "longshot" bets typically succeed around 14% of the time across political markets, but in military-linked contracts, success rates have exceeded 50% in some cases. 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 report's findings add to existing research indicating that a small group of traders, roughly 3%, drive price discovery on Polymarket, while 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, with eight wallets sharing about $1.8 million in profits. The pattern of well-timed bets on military and defense outcomes extends beyond a 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 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 on whether the public should be betting on these outcomes at all.