A Google software engineer has been charged with insider trading for allegedly turning confidential search data into profits on Polymarket. The case exposes a structural problem prediction markets have been quietly ignoring: every new contract listed creates a new attack surface, and every institution holding non-public information becomes a potential leak point.
The transparency paradox
Polymarket has emphasized cooperation with federal authorities, describing blockchain trading as transparent and traceable, with bad actors leaving footprints.
That framing is worth sitting with.
Prediction markets pitch themselves as efficient information aggregators, places where the wisdom of crowds prices probability more accurately than pundits or polls. But two prosecutions in quick succession suggest a different dynamic: when any verifiable fact about the world can be wagered on, every institution holding non-public information becomes a potential leak point. A search engine’s internal dashboards. A military operation’s classified briefings. A pharma trial’s preliminary readouts. The attack surface expands with the menu of contracts.
What the Justice Department alleges
Michele Spagnuolo allegedly traded on Polymarket under a specific username, according to the Justice Department. He risked more than $2.7 million on wagers tied to Google’s 2025 Year in Search, the company’s annual marketing campaign revealing the year’s most popular queries. Prosecutors allege Spagnuolo accessed confidential internal data about the most-searched celebrities, information available only to Google employees, and used it to position bets ahead of the public reveal, netting more than $1.2 million in trading profits. The Justice Department characterized the alleged conduct as motivated by greed.
Google’s response
A Google spokesperson confirmed the employee has been placed on leave and that the company is cooperating with law enforcement. The engineer accessed marketing material through a tool available to all employees. Using that confidential information to place bets constituted a serious breach of policy. Spagnuolo had worked at Google for more than 12 years.
The second Polymarket prosecution in months
The case follows a structurally similar prosecution earlier this year. The Justice Department charged a U.S. Army soldier with using classified information about a U.S. military operation to net roughly $400,000 on Polymarket. Different sectors, identical mechanism: a person with privileged access to information that will move a market, placing positions before that information becomes public.
Why this matters
Polymarket spent the past two years arguing, successfully in regulatory terms, that it should be treated as a legitimate financial venue rather than an offshore betting site. The cost of that legitimacy is now visible: cooperation with the Southern District of New York, subpoena-ready transaction records, and prosecutions that look indistinguishable from equities cases. The blockchain that made trades publicly auditable also made them publicly prosecutable.
So here is the question the next listing cycle will have to answer: if a prediction market only works when its prices reflect information the public does not yet have, and only survives when every leak gets traced back to a name, which version of itself is Polymarket actually building toward — the efficient aggregator, or the surveillance venue that punishes the people who make it efficient?
