Polymarket US and Kalshi fee gap narrows on 100-contract trades
A fee comparison by The Defiant finds that trading costs on Polymarket US and Kalshi can be closer than the price spread on a 100-contract trade. The analysis, published October 21, examines entry fees, early exits, settlement charges, and funding costs on the two CFTC-regulated platforms. Cryptonews.net reported similar findings on October 22. Both venues compete for U.S. eligible users in the regulated prediction markets space.
Fee parity changes how traders pick a venue. On a 100-contract position, the cost gap between Polymarket US and Kalshi shrinks to the point where price execution matters more than commission structure. That flips the competitive axis: liquidity depth and market-making quality decide where volume flows, not headline fee schedules. For Kalshi, which Needham estimates holds a 76% volume lead, this narrows a key advantage.
For Polymarket US, operated through QCX, it means the platform can compete on cost without running a race to zero. Traders who optimize for all-in cost now face a harder choice between two nearly identical fee profiles, pushing both venues to improve fills or lose flow to the other. The real winner is the user who shops both books.
Joins a running focus on Kalshi and Polymarket pricing dynamics after Kalshi retakes NFL pricing edge from FanDuel, DraftKings in Week 4 and a month in which the two platforms posted $53 billion combined volume.