A Google Engineer used confidential internal company data to place winning trades on a prediction market, earning $1.2 million before federal authorities arrested him, according to court documents.
Eng Tai, a software engineer at Google, accessed internal data related to Google Search traffic before placing bets on Polymarket, a decentralized prediction market where users wager on real-world outcomes, prosecutors said.
The Trades
Tai placed bets on whether Google Search traffic would rise or fall during specific periods. He had access to internal Search metrics through his job, which gave him information that outside traders did not have.
Federal prosecutors charged Tai with wire fraud and insider trading-related offenses. His access to non-public Search data, they said, gave him an illegal edge on a market where other participants were trading blind.
How Polymarket Works
Polymarket lets users buy and sell positions on the outcome of events — political races, economic indicators, corporate metrics — using cryptocurrency. Positions are priced between zero and one dollar, with a winning position paying out one dollar.
The platform operates on the Polygon blockchain, and trades settle automatically based on verified real-world outcomes. Because it uses smart contracts rather than a central counterparty, Polymarket is not regulated as a traditional exchange under U.S. law — though that legal gray area has not shielded users from federal prosecution where fraud is alleged.
The Broader Context
Insider trading law in the United States, enforced by the Securities and Exchange Commission and the Department of Justice, prohibits trading on material non-public information — typically in securities markets. Applying that framework to prediction markets is a developing area of law.
Still, prosecutors have shown willingness to pursue wire fraud charges in cases involving non-public information even outside traditional securities markets. Wire fraud, which carries a maximum 20-year federal prison sentence under 18 U.S.C. § 1343, does not require a securities market — only a scheme to defraud using electronic communications.
Tai’s case is among the first to test that theory in the context of a cryptocurrency-based prediction platform.
Polymarket gained significant public attention during the 2024 U.S. presidential election, when its odds on Donald Trump’s victory tracked closely with — and in some cases diverged sharply from — traditional polling aggregators. Daily trading volume on the platform surpassed $100 million on multiple occasions during that period, according to on-chain data tracked by Dune Analytics.
Google, one of the world’s largest companies by market capitalization, does not publicly disclose granular Search traffic data in Real Time. Employees working on Search infrastructure have access to internal dashboards and performance metrics that reflect traffic trends before any public disclosure.
The Department of Justice has not yet disclosed a trial date in the case.
