The alleged insider bet of $400,000 by a Green Beret on a Venezuelan raid may be just the tip of the iceberg. The Anti-Corruption Data Collective, a non-profit research organization, has analyzed over 435,000 Polymarket contracts from January 2021 to mid-March 2026, finding that low-probability bets on military and defense outcomes have success rates that are difficult to explain by skill or luck alone. Typically, such 'longshot' bets succeed around 14% of the time across political markets, but in military-linked contracts, success rates have exceeded 50% in some cases.
The authors of the report suggest that markets related to government policies, such as military and defense, are harder to forecast using public information and are more susceptible to information asymmetries, including insider trading. The gap between informed and uninformed traders may be widest in these markets, creating conditions where a small group can consistently outperform others. Polymarket has market surveillance teams and cooperates with the Department of Justice on the Venezuela case, and trading on confidential knowledge is prohibited on the platform.
The report's findings add to existing research indicating that a small percentage of traders account for most price discovery and profits on Polymarket. The analysis of the June 2025 US strikes on Iran as a case study found that a small number of traders placed large, well-timed bets on the outcome, despite the Pentagon's efforts to keep the operation secret. The pattern extends beyond a single event, with winning longshot bets outnumbering losing ones in five of the six two-hour windows before market resolution in Polymarket's military and defense category. While longshot bets can outperform for other 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. The conclusion calls for an evidence-informed debate on whether the public should be betting on these outcomes at all.