The House Committee on Oversight and Government Reform is formally investigating prediction markets Polymarket and Kalshi after a string of suspicious trades linked to classified U.S. military operations. Representative James Comer (R-KY) announced the probe on May 22, demanding that the CEOs of both platforms explain how they detect and prevent insider trading. The investigation follows the arrest of a U.S. special forces soldier who placed bets on Polymarket about the military incursion into Venezuela that captured President Nicolás Maduro — trades made hours before the operation became public.
Suspicious trades tied to military operations
Comer’s office pointed to several incidents. One trader accumulated nearly $1 million with a 93% win rate on wagers predicting unannounced U.S. and Israeli strikes against Iran, placing bets hours before operations in October 2024, June 2025, and February 2026. On February 28, 38 accounts collectively netted more than $2 million on bets tied to Iran strikes, with those accounts preloaded with funds the preceding week. Then on April 7, at least 50 newly created accounts placed coordinated bets on a U.S.-Iran ceasefire — some opened just minutes before the announcement. Polymarket separately reported suspicious activity across nearly 50 accounts in advance of those ceasefire talks.
Platforms update rules, but scrutiny continues
Both Kalshi and Polymarket announced updated rules and surveillance tools in March 2026. The changes restrict politicians from trading on their own campaigns and bar athletes from sports-related contracts. Combined trading volumes on the two platforms reached tens of billions of dollars in March alone. But the new rules didn’t stop Comer’s investigation. Kalshi, through head of communications Elisabeth Diana, said the company looks forward to engaging with the committee and described its insider trading protections as comprehensive. Polymarket did not immediately respond to a request for comment at the time of publication.
Political and lobbying ties under the microscope
The platforms share more than a business model. Both count Donald Trump Jr. as an advisor. And both spent a combined nearly $1 million on federal lobbying in 2025. Those connections are likely to come up as Comer’s committee examines whether the companies have done enough to stop people with non-public information from cashing in on geopolitical events.
What comes next
Comer has demanded that the CEOs of Polymarket and Kalshi provide detailed descriptions of their detection systems, along with records of suspicious trading activity and any internal investigations. The committee is waiting for responses. Whether the probe leads to new legislation or enforcement action remains an open question — but for now, both platforms are in the hot seat.
