Kalshi vs Polymarket 2026: Fees, Markets & US Legality

Two years ago the choice in the prediction market space was pretty straightforward. Polymarket was the crypto-native platform Americans weren’t meant to touch while Kalshi was the regulated US exchange that played by the book. Fast forward to today and there are multiple other prediction market platforms like Rothera, Predictdotfun, Opinion, Limitless etc that are looking to bite away at the market share. Despite competition ramping up, Kalshi and Polymarket are by far the leaders in terms of volume, number of trades and open interest. The line from two years ago, however, has mostly dissolved. Polymarket now runs a CFTC-licensed US arm and despite Kalshi fighting roughly a dozen states in the US over whether sports contracts count as gambling, the latest numbers on combined trading volume between the two platforms hit $47.5 billion in the month of June alone this year. That’s more than triple the roughly $14 billion a month US sportsbooks averaged in 2025, per Pew Research Center. Kalshi vs Polymarket at a Glance Kalshi Polymarket Underlying model CFTC-regulated exchange (DCM), central order book, settles in US dollars Onchain protocol on Polygon, order-book matching, settles in USDC Fees (taker/maker) Taker peaks near 1.75¢ per contract at 50¢, using the formula 0.07 × price × (1 − price); maker roughly a quarter of that. No ACH fee, up to 2% debit-card fee Category taker fees since March 30, 2026: up to $0.75 per 100 shares on sports, about $1.00 on politics, up to roughly $1.75 on crypto. Geopolitics markets are free. Makers pay $0 and collect rebates Markets offered Sports, politics, economics (CPI, Fed, GDP), finance, weather, culture, crypto prices, corporate events; a large curated catalog Sports, politics, crypto, finance, culture, mentions, geopolitics and world events; thousands of markets, including ones a US exchange can’t list US legality CFTC-licensed, technically legal in all 50 states and DC; sports contracts contested in about a dozen states, with split court rulings International platform geo-blocked in the US; Polymarket US (CFTC-licensed through its QCX purchase) is legal but separate, with much smaller liquidity Trading volume (June 2026) $33.0 billion $14.5 billion Custody USD held in segregated accounts under CFTC rules; USDC deposits safeguarded by Coinbase Custody; not FDIC-insured Self-custodied USDC in your own wallet or the market’s smart contract; not FDIC or SIPC insured Payouts/settlement Resolves within hours against named sources (AP, ESPN and the like); disputes run through a regulated process Settled by the UMA oracle plus an integrity committee; disputes go to a 48-to-96-hour vote; payout is instant once resolved Fees Compared Kalshi charges on nearly every trade. Polymarket, for most of its life, charged almost nothing.