A small number of gamblers have made $8 million placing military and defense-related bets on the Polymarket prediction site, most placed by about 150 accounts that almost always bet correctly. The researchers say they suspect the accounts are linked to military insiders who could be flagged for law enforcement as “the most likely potential insiders,†researchers said in a new report.
When the most successful of those accounts bet on unlikely military events, researchers found, they won virtually every single time.
“Traders acting on specialized, non-public information possess an edge that is valuable only within a limited set of markets, and that produces win rates difficult to attribute to luck,†researchers with the Anti-Corruption Data Collective said in a new report released Thursday. The researchers studied the small number of bettors who met two criteria: â€The concentration of their betting within less than 100 markets and two topics, and unusual accuracy (over 75%) of their longshot bets.â€
The same research group published a report in April that found a high risk of insider trading on military-related Polymarkets after observing that “longshot†bets on military operations won 52% of the time, which was four times more often than other types of markets.
While ‘whales' often lose, ‘orcas' almost always win
The collective's new report hones in on 152 accounts which researchers analyzed and found certain behaviors that “support our hypothesis that they are the most likely insiders.†The accounts, which researchers called “orcas†or “highly specialized, incredibly successful bettors,†were compared to whales, who spend the most on a wide range of markets to “devour enormous profits,†mostly at the expense of “small fish†bettors who tried their luck but end up “losing out badly to the fat larger competition.â€Â
The collective found that half of the orca accounts made their first long-shot bet within two days of making their Polymarket account and waged higher bets more often on high-risk, low-probability markets. The 152 orca wallets placed $2 million on military longshot bets and won 97.2% of the time for $8 million, or over $52,500 per wallet.Â
Despite spending overall less money on bets than others, orcas still made a return of 132% compared to whales and small fish whose losses were as high as -2%. At least half of the orcas doubled their money.
The trends could pose larger national security implications, the report said. The collective observed orcas placing bets first that were then followed by whales (a group which also may include bot accounts) and small fish. As an example, orcas made a series of longshot bets around Feb. 16, 2025, and again 48 hours before the U.S. began its March strikes on Iran. Those bets were followed by whales and potential bots.Â
“Because every Polymarket trade is visible on a public blockchain in real time, an insider betting on confidential military information is effectively broadcasting that information to foreign adversaries,†the collective said. “Copycat behavior amplifies these signals, making them virtually impossible to contain.â€
The collective also pointed out that Polymarket allows users to bet with cryptocurrency tools that make tracing an account to its owner next to impossible. As a result, pinpointing “potential suspicious activity,†like government officials or military personnel using non-public information for monetary gain, may not be possible. The report recommended that Polymarket require government-issued identification for all bettors.
The group's findings come amid ongoing insider betting cases involving U.S. and Israeli military personnel.
In April, U.S. Army Master Sgt. Gannon Ken Van Dyke, a special operations soldier, was arrested and charged for making more than $400,000 in Polymarket bets related to Venezuela and the U.S. raid and capture of Venezuelan President Nicolas Maduro. Van Dyke was on a Navy vessel that helped stage the raid. In April, he pleaded not guilty and last month his lawyers asked for the case to be dismissed, arguing that federal prosecutors were trying to stretch current laws to make them fit his case.
Several Israelis have also recently been arrested on suspicion of placing Polymarket bets based on classified information, including an arrest this month of an airman accused of using sensitive military information to bet on Iran and Yemen attacks. In May, Israel charged its first airman with similar crimes, and as part of his defense, the officer claimed that “The entire Israel Air Force is involved in gambling.â€
