The alleged insider bet of $400,000 by a Green Beret on a Venezuelan raid, initially thought to be an isolated incident, may be just the tip of the iceberg. The Anti-Corruption Data Collective, a nonprofit research organization, analyzed over 435,000 Polymarket contracts from January 2021 to mid-March 2026, totaling $54.4 billion in cumulative volume.

The results show that low-probability bets on military and defense outcomes have success rates that defy explanation by skill or luck alone, with some cases reaching over 50%. Typically, such "longshot" bets succeed around 14% of the time across political markets. The authors suggest that markets tied to government policies, such as military and defense, are particularly vulnerable to information asymmetries, including insider trading and 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 and cooperation with the Department of Justice, particularly in the Venezuela case, and prohibits trading on confidential information. However, the ACDC report contributes to a growing body of research indicating that a small percentage of traders, roughly 3%, drive most price discovery on Polymarket, with fewer than 1% of wallets capturing about half of all gains. The 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. Despite the Pentagon's efforts to keep the operation secret, a small number of traders placed large, well-timed bets on the outcome. This pattern is not isolated, as the report found that in five of the six two-hour windows before market resolution, winning longshot bets outnumbered losing ones in Polymarket's military and defense category.

While longshot bets can outperform due to various reasons, the consistency of these patterns, especially in markets tied to military decisions, suggests that some participants may have information advantages. The ACDC recommends identity verification for bettors, conditional payouts on suspicious wagers, restrictions on markets decided by small groups, and limits on contract granularity.

Ultimately, the report calls for an informed debate on whether the public should be allowed to bet on these outcomes at all.