The revelation of a Green Beret's alleged $400,000 insider bet on a Venezuelan raid initially seemed like an isolated incident. However, a new report suggests this might only be the tip of the iceberg, pointing to a potential insider trading crisis within Polymarket. The Anti-Corruption Data Collective, a nonprofit research organization, conducted an exhaustive analysis of over 435,000 settled Polymarket contracts from January 2021 to mid-March 2026, encompassing $54.4 billion in cumulative volume. The findings indicate that low-probability bets on military and defense outcomes achieve success rates that are challenging to attribute solely to skill or luck.
Typically, such 'longshot' bets across political markets succeed around 14% of the time, yet in military-linked contracts, success rates have reached as high as 50% in certain cases. The authors of the report noted that markets connected to specific government policies, including military and defense as well as foreign affairs, are particularly difficult to predict using publicly available information alone. This makes them more vulnerable to information asymmetries, including insider trading or specialized knowledge. In these markets, the gap between informed and uninformed traders may be the widest, creating an environment where a small group can consistently outperform others, not just by reacting more quickly, but by possessing more knowledge.
Polymarket emphasizes its market surveillance efforts and collaboration with the Department of Justice, particularly in the case involving Venezuela. The platform strictly prohibits trading based on confidential knowledge, a policy also upheld by Kalshi. The report's findings contribute to a growing body of research pointing in a similar direction. A working paper from the London Business School and Yale discovered that approximately 3% of traders are responsible for the majority of price discovery on Polymarket.
Separate analysis by the blockchain analytics firm Solidus Labs revealed that profits are even more concentrated, with less than 1% of wallets capturing about half of all gains. The ACDC report aims to shed light on the possible sources of this edge.
It examines the June 2025 U.S. strikes on Iran as a case study, focusing on date-specific contracts related to whether a strike would occur. The strike happened at 18:40 ET on June 21.
In the hours leading up to it, 19 longshot bets totaling $164,292 were placed across contracts that ultimately resolved in the affirmative. Eight wallets shared about $1.8 million in profits, with one wallet taking nearly $500,000.
The Pentagon had designed the operation to be undetectable from the outside, utilizing decoy bombers and long-range stealth aircraft to avoid detection. Despite these measures, a small number of traders placed large, well-timed bets on the outcome. This pattern is not isolated to a single event.
Across Polymarket's military and defense category, 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 would suggest. While longshot bets can outperform due to other factors such as mispricing or shifts in public expectations, the consistency of these patterns, especially in markets tied to military decisions, implies that some participants may be operating with information advantages not available to others. The ACDC, being a nonprofit research group funded through the Fund for Constitutional Government, does not have a surveillance product to sell, unlike Solidus Labs, whose recent Polymarket analysis also serves as a marketing case for the platform it licenses to Kalshi.
The ACDC's recommendations include implementing identity verification for bettors, conditional payouts on suspicious wagers, restrictions on markets whose outcomes are decided by small groups, and limits on how detailed contracts can become. The report concludes by calling for 'an evidence-informed debate about whether the public should be betting on these outcomes at all.'