House Oversight Committee Chairman James Comer has opened an investigation into prediction markets Kalshi and Polymarket over insider trading concerns. The probe, announced this week, zeroes in on whether the platforms let users trade on material non-public information — a practice that would violate federal securities laws if the contracts are deemed securities. The inquiry could ripple beyond the two companies, potentially tightening rules for an industry that has exploded in popularity during the 2026 election cycle.
Why Comer is looking at prediction markets now
The timing isn't accidental. Prediction markets have become a go-to source for real-time odds on everything from election outcomes to Fed rate decisions. But with that growth has come scrutiny. Comer's letter, sent to both exchanges, asks for detailed records on how they screen trades, handle whistleblower tips, and whether they've ever detected — and acted on — suspicious activity. The chairman has made no secret of his view that unregulated betting on political events could erode public trust in both markets and democratic processes.
What the investigation could mean for Kalshi and Polymarket
Both platforms operate in a legal gray area. Kalshi has a federal license from the Commodity Futures Trading Commission to offer event contracts, while Polymarket is built on blockchain and settles trades in USDC stablecoins. The probe doesn't single out a specific incident, but the insider trading angle suggests regulators may be worried about a loophole: if a trader learns a non-public fact about a candidate or a policy change, they could profit before the news breaks. If the investigation leads to formal charges or a referral, it could force Kalshi and Polymarket to overhaul their compliance systems — or face suspension of some contracts.
The broader regulatory stakes
This isn't just a two-company problem. The investigation could embolden the SEC and CFTC to treat prediction-market bets as securities or commodities more aggressively. That would raise costs for every operator in the space. User trust is fragile — if a platform is seen as a haven for insiders, retail traders will walk. Comer's probe may also prompt other lawmakers to draft legislation explicitly defining how prediction markets should police insider trading. For now, the exchanges have said they will cooperate. The committee expects responses within the next 30 days.
