A US Army Master Sergeant has been indicted for allegedly using classified military information to place bets on Polymarket, reportedly turning roughly $34,000 into more than $400,000. It is the first federal prosecution for insider trading tied to a prediction market, and it is forcing Washington to reckon with a regulatory blind spot that has been hiding in plain sight.

The Department of Justice unsealed the indictment of Gannon Ken Van Dyke on April 23, charging him with leveraging privileged intelligence about the potential ouster of Venezuelan leader Nicolás Maduro to place highly targeted wagers on the blockchain-based platform. The case has since snowballed into a congressional investigation and a broader reckoning for the entire prediction market industry.

The bet that broke the dam

Van Dyke, a Master Sergeant with access to classified military intelligence, placed bets totaling between $33,000 and $34,000 on Polymarket. Those bets were tied to events surrounding the anticipated removal of Maduro in Venezuela. The result: profits exceeding $400,000.

An analysis published in May 2026 by blockchain analytics firm Bubblemaps identified nine connected accounts on Polymarket that collectively earned over $2.4 million. Their win rate on military-related bets: 98%.

Polymarket’s preemptive rule change and the congressional probe

Polymarket updated its trading rules in March 2026, a month before the indictment dropped. The revised rules explicitly prohibit betting based on information obtained through breaches of trust, with particular emphasis on individuals who are in a position to influence the outcomes they are wagering on.

The fallout has now reached Capitol Hill. Rep. James Comer initiated a congressional probe on May 22, sending document requests to both Polymarket and its competitor Kalshi. The investigation is focused on what insider trading safeguards these platforms have in place, and whether the current regulatory framework is equipped to handle markets where geopolitical events are the underlying asset.

Kalshi, which has positioned itself as the more regulation-friendly alternative by operating under CFTC oversight, is not immune either. Comer’s document requests went to both platforms, signaling that Congress views this as an industry-wide problem rather than a single-platform failure.