The U.S. House Oversight Committee plans to open an investigation into the largest prediction market platforms over suspicions that government employees may exploit classified information for personal gain.
Rep. James Comer, R-Ky., chairman of the House Oversight and Government Reform Committee, is reviewing the internal records of Polymarket and Kalshi CEOs to determine whether government employees are using inside knowledge to profit from geopolitical and military policy and operations, he said Friday on CNBC’s Squawk Box.
“There’s now a fear that members of Congress, members of the presidential administration, any type of government employee, can use basic insider knowledge and make huge profits on anything government-related,” Comer told CNBC.
“So we want to not only launch an investigation to see how widespread this has become so far, but also prove that we need to pass some sort of legislation,” Comer added. “And I think it wouldn’t be too much to ask to say that members of Congress cannot participate in the forecast market, nor can government employees or members of the presidential administration.”
Comer’s investigation is the latest in a series of congressional attempts to investigate prediction markets and control insider trading.
In letters sent Friday to Polymarket’s Shayne Coplan and Kalshi’s Tarek Mansour, Comer requested clarification on how the platforms handle identity verification, enforce geo-restrictions and report anomalous trading activity.
Prediction markets, which have gained popularity in recent years, have attracted the attention of federal and state lawmakers and regulators, who fear the platforms are ripe for exploitation by bad actors with national security clearances.
Prediction market volumes could peak at around $1 trillion by 2030, as the industry evolves from niche betting to large-scale “information markets” spanning sports, crypto, politics and economics, according to a report from Wall Street broker Bernstein in April. Volumes reached $51 billion last year and could reach around $240 billion in 2026.
The House investigation follows a heated U.S. Senate Commerce Committee hearing on Wednesday, during which lawmakers from both parties closely scrutinized prediction market platforms like Kalshi and Crypto.com. Senate Commerce Chairman Ted Cruz (R-Texas) blasted the industry for enabling cheating scandals in major sports leagues, warning that the opportunity to profit from event contracts tempts athletes and officials to manipulate results. Meanwhile, Senator John Hickenlooper (D-Colorado) accused the companies’ aggressive marketing on social media of “preying on our young people” and encouraging problem gambling.
Nicolas Vaiman, co-founder and CEO of on-chain intelligence layer Bubblemaps, expressed deep concern about the national security implications of a new wave of insider trading in an interview with CoinDesk.
He warned that if those who watch forecast markets can spot irregular trading, so can enemies of the United States. He and his team found 80 bets on Polymarket with a 98% success rate, which he says is statistically impossible to achieve. “Not even luck can explain these victories.”
