Polymarket Faces Insider Trading Scrutiny Across 150 Wallets

Anti-Corruption Data Collective (ACDC) has identified what it describes as insider-trading patterns on Polymarket, focusing on 556 wallets labeled Orcas that opened accounts, placed large long-shot bets on low-odds outcomes, and then cashed out. Of these, 152 wallets generated about $8 million in profits with an average win rate of 97.2%, predominantly in military and defense markets. Researchers warn that such unusual activity is highly visible and often copied by large traders and bots, and they caution that foreign intelligence services could be monitoring these markets. Polymarket and the Department of Defense did not immediately comment on the findings, which arrive amid other instances of alleged market manipulation and recent coverage of related bets that drew scrutiny. The broader context includes regulatory interest and global scrutiny of prediction markets, including a crackdown that led to Polymarket-related access blocks in places like South Korea. While ACDC notes that the observed pattern could reflect luck or other explanations besides illicit activity, it raises questions about the integrity and transparency of prediction markets when nonpublic information appears to influence trading outcomes.