How Online Sleuthing Caught the Google Polymarket Insider Trader

Google Employee Accused of Insider Trading on Polymarket

Late last year, blockchain engineer Haeju Jeong noticed a mystery trader on Polymarket had earned over $1 million with uncannily accurate bets on top Google search results of 2025. He shared his suspicions online, and the post went viral.

Now, federal prosecutors allege that longtime Google software engineer Michele Spagnuolo used access to internal company data to place the lucrative bets. Spagnuolo is charged with fraud and money laundering.

How Amateur Sleuths Help Law Enforcement

Prediction markets like Polymarket create tempting opportunities for those with nonpublic knowledge. However, blockchain-based transparency allows amateur sleuths to spot suspicious activity in near real-time. These sleuths often remain anonymous and highlight concerns on social media.

Polymarket does not require proof of identity, making it largely anonymous. But its blockchain technology enables anyone to monitor bets, profits, and losses of individual accounts, making it easier to detect suspicious activity.

How the Trader Was Caught

Spagnuolo used sophisticated techniques to mask his identity, including crypto transfer services with privacy protection. However, the FBI identified him through an earlier withdrawal. In November, he moved $149,980 off Polymarket to a crypto swapping service, and soon after, identical funds reached a payment processor account in his name.

Blockchain analytics firm Bubblemaps identified the platforms used. Experts note that bettors who want to convert crypto winnings into traditional currencies eventually need to use banks or regulated exchanges, making it possible for authorities to identify them.