The alleged insider bet of $400,000 by a Green Beret on a Venezuela raid, initially thought to be an isolated incident, may be just the tip of the iceberg. A recent report by the Anti-Corruption Data Collective (ACDC) analyzed over 435,000 settled Polymarket contracts, spanning from January 2021 to mid-March 2026, with a cumulative volume of $54.4 billion.
The findings indicate that low-probability bets on military and defense outcomes have success rates that defy explanation by skill or luck alone, with some cases reaching success rates of over 50%. In contrast, the typical success rate for such 'longshot' bets across political markets is around 14%.
The authors of the report suggest that markets tied to specific government policies, including military and defense, are more susceptible to information asymmetries, which can include insider trading or specialized knowledge. This creates an environment where a small group of informed traders can consistently outperform others, not just by reacting faster, but by possessing more knowledge.
Polymarket emphasizes its market surveillance teams and cooperation with the Department of Justice, particularly in the Venezuela case, and prohibits trading on confidential knowledge on its platform, as well as on Kalshi. The report's findings add to existing research indicating that a small percentage of traders drive most price discovery on Polymarket, with roughly 3% of traders accounting for the majority. Furthermore, analysis by blockchain analytics firm Solidus Labs shows that profits are highly concentrated, with less than 1% of wallets capturing about half of all gains.
The ACDC report contributes to this body of research by suggesting a possible source of this edge. The report examines the June 2025 U.S. strikes on Iran as a case study, where Polymarket listed several date-specific contracts on whether a strike would occur.
The strike happened at 18:40 ET on June 21, and in the hours leading up to it, 19 longshot bets totaling $164,292 were placed across contracts that ultimately resolved YES. Eight wallets shared about $1.8 million in profits, with one wallet taking nearly $500,000. The Pentagon had designed the operation to be unreadable from the outside, using decoy bombers and long-range stealth aircraft to avoid detection.
Despite this, 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 imply. While longshot bets can outperform due to mispricing or shifts in public expectations, the consistency of the patterns, especially in markets tied to military decisions, suggests that some participants may be operating with information advantages that others do not have. The ACDC, as a nonprofit research group funded through the Fund for Constitutional Government, has recommended several measures, including identity verification for bettors, conditional payouts on suspicious wagers, restrictions on markets whose outcomes are decided by small groups, and limits on how granular 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.