Polymarket vs Kalshi (2026)

Neither, categorically. Kalshi offers CFTC-regulated USD trading with strong economics and sports coverage; Polymarket offers zero-fee standard markets and the deepest liquidity on politics and global events. On any single question, the better platform is the one quoting the better all-in price — which changes market by market. That per-question comparison is exactly what this site does.

It depends on the month and the category. Polymarket led on total volume through the 2024 election cycle; Kalshi's sports event contracts pushed it ahead on several 2026 months. The 'Which is bigger' section on this page shows the live open-market footprint we track for each, and the head-to-head table shows where each one is deepest.

Yes. Kalshi is a CFTC-regulated designated contract market — a federally regulated exchange where US residents trade in dollars. Its sports event contracts have been challenged by some state regulators, and federal courts have so far largely sided with Kalshi, but that area remains in motion.

Yes — through its US app. After a 2022 CFTC settlement, Polymarket blocked US users for years; it acquired the CFTC-licensed exchange QCEX in 2025 and launched a regulated US app in December 2025, dropping the waitlist in mid-2026. The global crypto platform remains unavailable to US residents, and the US app is excluded in a handful of states.

Polymarket charges no trading fee on standard binary markets — a few product categories carry taker rates — so your costs are mostly the spread and money movement. Kalshi charges a taker fee of 0.07 × price × (1 − price) per contract — about $1.75 per 100 contracts at 50¢, far less near the extremes — with a 75% discount for resting maker orders on eligible markets. A 1–2¢ better sticker price on Kalshi can be erased by the fee near 50¢.

Sometimes, and the arbitrage section on this page shows the live candidates: buy YES on the cheaper venue and NO on the other, and if the two prices plus Kalshi's fee add up to less than $1 the position pays $1 whichever way it resolves. In practice the gap has to beat Kalshi's fee, the spread on both books, and the risk that the two contracts settle on subtly different rules — most gaps under 3¢ are not worth the capital.

There is no consistently better venue — the same question trades a few cents apart in either direction, market by market. What matters is the fee-inclusive price: Kalshi's sticker price needs to be better by more than its taker fee to actually be better. Our matched-market table shows both quotes side by side so you can take the cheaper one.

PredictIt is the oldest of the three, a US political-markets site that historically operated under a CFTC no-action letter with an $850 per-contract cap and a 10% fee on profits; its regulatory footing has been changing in 2025–26. Kalshi is a full CFTC exchange with no comparable cap and markets across sports, economics and politics. Polymarket is the crypto-native global venue with a regulated US app. For politics, all three overlap; for anything else it is Polymarket or Kalshi.

They overlap heavily on major questions — elections, Fed decisions, economic data, big sports and world events — but word and settle them differently. Our matching pipeline links the pairs that genuinely ask the same thing; those validated pairs are what power the live comparison on this page.

Different user bases, different fees, different access frictions, and different resolution rules. The gaps are real but not free money: closing one means paying Kalshi's fee, moving money onto two venues, and carrying the risk that the two contracts settle on subtly different terms.

Yes, and active traders increasingly do — buy where the question is cheap, sell where it's rich, or simply take each position on whichever venue prices it better. The practical hurdle is capital in two systems: USDC on one side, a KYC'd dollar account on the other.

Kalshi offers sports event contracts — federally regulated contracts on game outcomes, which trade like its other markets rather than like a sportsbook bet (you can exit mid-game at the market price). Several state regulators have contested them; federal courts have so far largely let them stand.

Manifold uses play money, which makes it a forecasting community rather than a trading venue — useful signal, no capital at risk. We track it alongside Polymarket and Kalshi; where all three price the same question, the site shows them together.