Polymarket vs Kalshi

Polymarket publishes the whole schedule and it is not free, which is a change worth flagging if you last checked a while ago. Makers are never charged. Takers pay a rate set per category — 0.07 on crypto, 0.05 on sports, 0.04 on finance and politics, zero on geopolitics — applied as shares × rate × p × (1 − p). Because of that last term the cost peaks at a quarter of the headline rate when a contract trades near 50¢ and decays toward the tails: a $1.75 charge for 100 crypto shares at 50¢ ($50 trade cost), or $1.00 for politics. Those amounts equal 3.5% and 2% of purchase cost respectively. Polymarket charges nothing to deposit or withdraw USDC, though whichever intermediary you use may.

Kalshi’s July 2026 schedule uses a general taker formula of 0.07 × series multiplier × contract count × price × (1 − price), rounded up to a cent. Some series have different multipliers or fee treatment. Its maker schedule also contains exceptions, so a blanket free-maker claim would be misleading.

One asymmetry that does not depend on the missing schedule: Kalshi states a 2% processing fee on debit-card deposits, which on a small first deposit can exceed anything either venue charges to trade.

Both are broad, and both taxonomies cover every category we track. Kalshi’s own API returns 14 series categories: Climate and Weather, Commodities, Companies, Crypto, Economics, Elections, Entertainment, Financials, Mentions, Politics, Science and Technology, Social, Sports and Transportation. Polymarket’s fee schedule enumerates 11: crypto, sports, finance, politics, tech, mentions, economics, culture, weather, other and geopolitics.

What we cannot tell you is how many markets are live on each, or which lists a breaking event faster — the two things people usually mean by “more markets”. Both require sampling the venues over time, and our market-variety ratings rest on the published category lists alone. Treat the near-identical ratings as “both broad” rather than as a measured tie.

Kalshi appears on the CFTC’s Designated Contract Market register as “Kalshi — Designated — 11/03/2020”, the venue itself rather than an affiliate, and the oldest designation among the platforms we track. Its Member Agreement does not list the United States as a restricted jurisdiction and names no US state; the United Kingdom is listed and is prohibited.

Polymarket is two things and this page reviews the offshore one. The register does list “QCX LLC d/b/a Polymarket US — Designated — 07/09/2025”, with the register’s own remark that QCX now operates under that assumed name — but that designation belongs to the US entity, and the book at polymarket.com holds no licence we can name, with an operating company whose jurisdiction of incorporation we could not establish. Polymarket’s own geo documentation puts the United States, United Kingdom, Germany and Brazil among restricted jurisdictions where users may close positions but not open them.

The practical reading: if you are in the US and want Polymarket, the thing you would be signing up to is a different venue from the one scored on this page, and we have not verified its scope.

Kalshi is a fiat account. USD throughout, a $10 minimum except by wire at $1,000, deposits by debit card including Apple and Google Pay, ACH, PayPal, Venmo, Cash App, crypto, wire or real-time payments, and withdrawals by card, bank, crypto, PayPal or Venmo. Identity verification is mandatory — legal name, date of birth, a residential address with no PO boxes, and a live photo of a government ID — and Kalshi says the CFTC may additionally require proof of address, employment information or source of funds. It also places temporary holds on deposited funds before they can be withdrawn, varying by method.

Polymarket is self-custody. Deposits arrive as USDC across Polygon, Arbitrum, Base, Optimism and other EVM chains, plus Solana, Bitcoin and Tron, and convert to pUSD as trading collateral; the stated minimum is $2 on the L2s, $7 from Ethereum and $9 from Bitcoin or Tron. Whether Polymarket requires identity verification is not stated on any page we could read, so we make no claim either way — and we removed the “No KYC” badge this record used to display, because an unread page is not evidence of no requirement.

Both Editor Scores on this page are preliminary and the badge appears next to each. Three of the nine criteria are unrated on both platforms: liquidity, because the order-book and volume data needed to measure spreads and depth sits behind redistribution terms we do not hold; and interface and support, because rating those means opening an account, trading and contacting a support desk, and nobody here has. Resolution is rated on both, from Kalshi’s own rulebook and from Polymarket’s and UMA’s documentation of the optimistic oracle.

That matters for how you read the comparison. Kalshi’s higher score is assembled from regulation, market breadth, payments and promotions — its strong criteria — while its fees are unrated. Polymarket’s includes a fee rating and excludes payments. The scores are honest about their own coverage, but they are not two equally-measured numbers, and the criterion breakdown on each review page shows exactly which weight was applied.