A new study from the Anti-Corruption Data Collective has classified 556 Polymarket wallets as likely insider traders, known internally as “Orcas.” The report, “Classifying Insider Trading Risk,” reviewed 78,496 longshot bets placed by 12,355 wallets on the prediction platform. ACDC defined a longshot as a wager of more than $2,500 at a price of 35 cents or less, meaning the outcome had a 35% chance or worse.
Researchers split the sampled wallets into four groups: Orcas, Whales, Bots, and Small Fish. The 556 Orcas placed targeted bets in only a small number of markets and won at a rate above 75%, compared with 3,278 high-volume Whales, 760 partly automated Bots, and 7,761 Small Fish. ACDC found that across all Polymarket longshot bets, only 14% win, but the win rate rises to 25% in political markets and reaches 52% in military and defense markets. The report’s authors, Michelle Kendler-Kretsch and David Szakonyi, counted $9.3 million in winning longshot bets from military markets alone.
The report also highlights national security concerns tied to blockchain transparency. When an Orca bet on U.S. military action in Iran hours before the June 2025 strikes, a Bot and a Whale placed copycat bets of $200,000 and $100,000, respectively. ACDC said this copycat activity is legal but can broadcast insider-like signals to foreign militaries and intelligence services in real time. It concluded that banning the highest-risk market categories outright is the only solution.
The findings follow several earlier insider trading cases involving prediction platforms. In April, the Justice Department charged U.S. Army soldier Gannon Ken Van Dyke with using classified details of the raid that captured Nicolás Maduro, allegedly staking about $33,034 and collecting roughly $409,881. In May, prosecutors in the Southern District of New York charged Google engineer Michele Spagnuolo with using internal company data to win $1.2 million on Polymarket. Bubblemaps also told CBS’s “60 Minutes” it had traced nine linked accounts that won more than $2.4 million across more than 80 Iran war bets at a 98% win rate, with CEO Nicolas Vaiman saying: “Luck alone cannot explain those numbers.”
