The U.S. House Oversight Committee is launching a sweeping investigation into the nation's largest prediction market platforms, with Chair Rep. James Comer demanding internal records from Polymarket and Kalshi amid allegations that government employees may be using classified information to generate significant trading profits on policy and geopolitical events.

Market Context

Prediction markets have surged in popularity over recent years, evolving from niche wagering platforms into broad-based "information markets" spanning sports, crypto, politics, and the economy. The sector handled $51 billion in volume last year and is projected to reach approximately $240 billion in 2026, with Bernstein analysts forecasting potential peaks of $1 trillion by 2030. This explosive growth has attracted intense regulatory scrutiny from both federal and state lawmakers concerned about national security implications.

Analysis

Comer, R-Ky., sent formal letters Friday to Polymarket CEO Shayne Coplan and Kalshi CEO Tarek Mansour requesting comprehensive documentation on how the platforms handle identity verification, enforce geographic restrictions, and flag anomalous trading activity. The congressman appeared on CNBC's Squawk Box to outline the probe's scope.

"There's a concern now that members of Congress, members of the president's 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 been thus far, but also to prove a case that we've got to pass some type of legislation."

The House probe follows a contentious Senate Commerce Committee hearing Wednesday where lawmakers from both parties criticized prediction market platforms. Sen. Ted Cruz, R-Texas, blasted the industry for enabling cheating scandals across major sports leagues, warning that profit opportunities on event contracts tempt athletes and officials to manipulate outcomes. Meanwhile, Sen. John Hickenlooper, D-Colo., accused the firms of aggressive social media marketing that "preys on our young people" and fosters problem gambling.

On-chain intelligence firm Bubblemaps flagged particularly concerning findings. Co-founder and CEO Nicolas Vaiman expressed alarm over national security implications, noting his team identified 80 bets on Polymarket with a 98% win rate—performance he described as statistically impossible to achieve through chance alone.

"Not even luck can explain those wins," Vaiman told CoinDesk in an interview, warning that if observers can spot irregular trades on prediction markets, so can adversaries of the United States.

Key Numbers

- $51 billion: Prediction market volume in 2025

- ~$240 billion: Projected sector volume for 2026

- $1 trillion: Bernstein forecast for peak sector volume by 2030

- 98%: Win rate on 80 flagged Polymarket bets identified as statistically anomalous

What to Watch

Comer indicated the investigation could support legislation barring members of Congress, administration officials, and government employees from participating in prediction markets. The probe's outcome may significantly reshape how these platforms operate domestically and could set precedent for future regulatory frameworks around event-based contracts. Congressional observers should monitor for document production deadlines and any subsequent hearings scheduled by the House Oversight Committee.

The SEC and CFTC, which have jurisdiction over different aspects of prediction market activity, may face pressure to clarify regulatory boundaries depending on investigation findings.