Live head-to-head data comparing Polymarket and Kalshi - volume, liquidity, structure, and where their odds diverge on matched questions right now.
Kalshi suits traders in the US and its other supported countries who want a CFTC-regulated exchange and dollar settlement. Polymarket.com suits traders in its supported countries who want on-chain settlement in pUSD; US residents who want Polymarket use the separate Polymarket US app.
| Metric | Polymarket | Kalshi | What this means |
|---|---|---|---|
| Open markets | 19,315 | 14,171 | How many questions are live and accepting orders right now. |
| 24h volume | $51.4M | $95M | Trading activity in the last 24 hours, each venue's own reporting basis (see methodology). |
| Open-market volume | $6B | $2.2B | Cumulative volume of each venue’s currently-open markets; totals move as markets open and settle. |
| Liquidity / open interest | $829.3M | $1.3B | Polymarket: order-book liquidity as the venue reports it. Kalshi: open interest, the outstanding contract notional, not order-book depth. Not directly comparable. |
Latest market snapshot recorded: Oct 20, 2026, 11:29 PM (Polymarket), Oct 20, 2026, 11:29 PM (Kalshi), UTC. Individual markets may be older.
Volume is reported on each venue's own basis: Polymarket volume is traded on-chain value in pUSD, a token backed 1:1 by USDC. Kalshi volume is settlement notional (contracts times $1), the basis Kalshi itself reports. The two figures are each venue's own authoritative number, not a normalized apples-to-apples comparison. Volume and liquidity totals cover currently-open markets: when a market settles, its volume leaves the totals, so day-over-day totals can fall as well as rise.
Kalshi is a CFTC-regulated exchange (designated contract market). It accepts US residents and traders in many other countries, except the restricted jurisdictions in its member agreement, and its contracts settle in US dollars under CFTC oversight. Polymarket.com is an international on-chain market that is not regulated by the CFTC and does not allow US persons to trade; it settles in pUSD, a token backed 1:1 by USDC. US residents can use the separate Polymarket US app, which is a CFTC-regulated exchange.
Kalshi settles internally as a regulated exchange and reports its own settlement notional as volume. Polymarket settles on-chain: every trade and resolution is a public, independently verifiable blockchain transaction.
Kalshi runs a central limit order book; contracts are quoted in one-cent steps and each winning contract pays $1. Polymarket also trades on a peer-to-peer order book (CLOB), with shares priced between $0 and $1, and each winning share redeems for $1 in pUSD.
Kalshi generally charges takers (orders that match immediately); some markets also charge makers (resting orders that fill later), rates vary by market, and canceling a resting order is free. Polymarket.com charges takers (orders that take liquidity) a fee on certain markets: shares × fee rate × p × (1 − p), where p is the share price in dollars (0 to 1) and the fee rate varies by market; makers never pay, and geopolitics and world-events markets are fee-free.
Kalshi accepts debit card (including Apple Pay and Google Pay), bank transfer (ACH), PayPal, Venmo, Cash App (deposits only), crypto and wire transfer, with a $10 minimum ($1,000 by wire); methods depend on your account and location (PayPal and Venmo are for US users and not available in every state). International accounts deposit by debit card, crypto or wire and withdraw by debit card or crypto. Polymarket.com is funded by transferring crypto (Polygon and other EVM networks, Solana or Bitcoin) and charges no fee to deposit or withdraw USDC, though intermediaries such as Coinbase or MoonPay may charge their own.
Kalshi offers a downloadable profit and loss statement and issues IRS forms by activity to users who meet IRS reporting thresholds: 1099-B for broker proceeds from crypto transfers, 1099-MISC for rewards and 1099-INT for interest, while 1099-DA for digital-asset activity comes from ZeroHash; gains and losses use first in, first out. On Polymarket.com, keep your own trade and transfer records and check your account or Polymarket support for the tax documents available to you; the public wallet activity feed is not itself a tax report.
Venue terms change. Checked on September 26, 2026 against each venue's own documentation:
Matched questions currently listed on both Polymarket and Kalshi, with each venue's current probability and the gap between them.
Probabilities can be stale or settle differently across venues. Check each source before trading.
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Data by CoinRithm - https://www.coinrithm.com/en/prediction-markets/compare/polymarket-vs-kalshi