Kalshi CEO Tarek Mansour does not see Polymarket as his main competitor. He told Front Office Sports that larger trading and betting players threaten his prediction market exchange more than its closest rival.
Mansour named derivatives giant CME Group, brokerage Robinhood and sportsbook operators as the rivals he watches most. His comments recast a fight usually framed as a two-horse race between Kalshi and Polymarket.
Why Mansour Looks Past Polymarket
Kalshi dominates the regulated US prediction market. Bank of America analysts put its share at about 91%, with Polymarket second and Underdog third.
That lead lets Mansour treat the rivalry differently, much as Kalshi already overtook Polymarket on regulated turf last year.
Raw volume tells a closer story. Over the past 30 days, Kalshi traded about $9.8 billion against Polymarket’s $9.9 billion, according to DeFi Rate.
Kalshi still leads where it counts. It holds roughly $1 billion of the $1.6 billion in industry open interest and lists about 97% of all active markets.
“When I think about competition, I don’t think about Polymarket, honestly, as much as some of the others,” FOS reported, citing Tarek Mansour, Kalshi CEO.
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A Wider Field of Rivals
Mansour pointed first to CME Group, which launched FanDuel Predicts with the sportsbook in December. The app trades event contracts on sports outcomes and economic data.
Robinhood complicates the picture. It built its prediction markets hub on Kalshi’s own exchange in 2025. It then began routing some World Cup and baseball contracts to Rothera, its venue with Susquehanna.
DraftKings, Novig and Coinbase have also moved into prediction markets, making second place hard to call.
Polymarket still leans on its offshore platform, which draws heavy offshore trading volume from US users on a VPN.
The 2026 World Cup lifted both, with a single World Cup winner market drawing tens of millions in daily bets.
Regulation Shapes the Rivalry
Mansour wants Polymarket to come under the regulated umbrella. He argued that insider trading cases on its international platform stain the whole industry.
Two indictments sharpened that worry. Prosecutors charged Army soldier Gannon Van Dyke in the first federal case tied to prediction market bets. He allegedly turned about $33,000 into more than $400,000 on the timing of the Maduro operation.
Weeks later, prosecutors indicted Google engineer Michele Spagnuolo. He allegedly made roughly $1.2 million betting on Google’s most-searched person of 2025.
The CFTC then proposed a 267-page rule on June 10. It would permit most sports contracts while barring in-game props, officiating bets and pre-collegiate sports, with a 45-day comment window.
Both platforms also gained reach this year when Google Finance integrated their data.
For now, Kalshi controls the compliant US market while Polymarket and a widening field chase its lead.
The comment period may decide how fast that balance shifts.