Polymarket vs Kalshi (2026)

Neither, categorically. Kalshi offers CFTC-regulated USD trading with strong economics and sports coverage; Polymarket offers the deepest liquidity on politics and global events, and charges takers less than Kalshi on most categories. 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 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 Polymarket US, a separate CFTC-regulated venue built on its acquisition of the licensed exchange QCEX. It is a different order book with its own fee schedule (a flat 0.0695 taker rate on all markets). The global crypto platform — the one whose prices this page quotes — is not open to US residents, and state-level eligibility for the US app is set by Polymarket, not by us: check its own terms before assuming access.

Both charge takers, and both use the same shape of formula. Polymarket (global) charges takers rate × contracts × price × (1 − price), where the rate is 0.04 on politics, finance, tech and mentions, 0.05 on sports, economics, culture, weather and other, 0.07 on crypto, and 0 on geopolitics; makers are never charged. Polymarket US charges a flat 0.0695 on all markets. Kalshi charges takers 0.07 × contracts × price × (1 − price), rounded up; its maker multiplier is 0 by default, so resting orders pay nothing except on the series Kalshi lists as non-standard. At 50¢ that is $1.75 per 100 contracts on Kalshi against $1.00 on a Polymarket politics market.

Not from the numbers on this page. The table shows each venue's most recently synced price — Kalshi's last trade and Polymarket's displayed price — and a gap between them is a gap before fees and before either book's bid/ask. We do not collect bid, ask or order-book size, so nothing here tells you what either leg would actually fill at. Beyond that, both venues charge takers, the two contracts settle under different rulebooks and deadlines, the capital is tied up until resolution, and eligibility to hold both legs differs by jurisdiction. Treat a gap as a starting point for your own checks on the venues themselves, not as a profit.

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 you can actually fill at: each venue's sticker price has to beat the other's by more than the difference in taker fees, and you pay the ask, not the last trade. Our matched-market table shows the latest synced price on each side so you know where to look; the venues' own order books decide the rest.

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 side-by-side table on this page. Matching is at the level of the question, not the rulebook — two matched contracts can still settle on different sources and deadlines.

Different user bases, different fees, different access frictions, and different resolution rules. A gap is not money on the table: closing one means paying a taker fee on both venues, crossing a bid/ask on both books, moving money onto two venues that not everyone can open accounts on, 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.