Polymarket bettors appear to have insider-traded on a market designed to catch insider traders - CoinDesk

Markets Share Polymarket bettors appear to have insider-traded on a market designed to catch insider traders At least 12 wallets collectively made over $1 million betting on the outcome of ZachXBT's investigation before the findings went public, with one trader turning a $0.14 average entry on shares into $411,000 in profit. By Shaurya Malwa|Edited by Sam Reynolds Updated Feb 27, 2026, 12:47 a.m. Published Feb 27, 2026, 12:43 a.m. Make preferred on What to know: A Polymarket prediction market on which crypto firm ZachXBT would accuse of insider trading saw about $40 million in volume before he named Axiom as the target. On-chain analysts say a small cluster of newly created wallets bet heavily on Axiom just before the reveal, generating more than $1 million in profit and suggesting someone had advance knowledge. Because Polymarket does not require identity checks and Axiom employees knew of the investigation ahead of publication, any potential insider betting may be difficult to trace even as Axiom says it is investigating. Can you insider-trade on an investigation into your own insider trading? Polymarket just turned that question from philosophical to practical. Blockchain sleuth ZachXBT published findings Thursday morning naming Axiom, a crypto trading platform, as the company whose employees he believed had used non-public information to place profitable trades. The investigation had been teased for days, and Polymarket had created a contract allowing users to bet on which company would be named, pulling in roughly $40 million in volume since Monday. The problem is that someone clearly knew the answer before it dropped. Lookonchain identified 12 wallets that bet heavily on Axiom before the reveal, netting a combined profit of over $1 million. A separate analysis by Polysights, a data terminal that tracks suspicious activity on Polymarket's public ledger, flagged five wallets that collectively wagered around $50,000 and walked away with $266,000. More on-chain data analyzed by CoinDesk tells the full story. The largest Yes holder on the Axiom market, an account called predictorxyz, accumulated 477,415 shares at an average price of $0.14 and is now sitting on $411,000 in profit. That's roughly a 7x return on a bet placed before the answer was public. The second-largest holder, an anonymous wallet, bought 109,450 shares at $0.33. The concentration is notable. This wasn't a broad market full of informed guesses. A handful of wallets dominated the Axiom side of the book. For most of the week, another platform called Meteora had been the market's frontrunner at over 50% odds, as CoinDesk reported. The odds swung to Axiom on late Wednesday, which peaked at 46.2%. Anyone buying Axiom shares in the window between that denial and ZachXBT's Thursday morning publication was either reading the room extremely well or already knew what was coming. ZachXBT acknowledged on social media that he had contacted Axiom for comment and conducted several interviews before publishing, making a leak "probably inevitable." That means multiple people at the company knew the report was coming before it went live. Any of them could have placed bets directly or tipped someone who did. Polymarket's offshore platform doesn't conduct identity checks, making attribution difficult without cooperation from the exchange itself. Axiom said it was "shocked and disappointed" by the findings and would continue to investigate. It didn't respond to questions about whether it was aware of any employees trading on the Polymarket wager. The structural irony here is that the mechanism worked exactly as designed. 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