Kalshi and Polymarket US are both exchanges regulated by the Commodity Futures Trading Commission (CFTC). Both take US dollars, hold full collateral, and have the exchange itself decide how a market resolves. Polymarket’s international site settles in a USDC-backed token on the Polygon blockchain, lists the United States as a restricted jurisdiction, and resolves most markets through UMA’s optimistic oracle, where anyone can propose an outcome and anyone can dispute it. On fees, all three charge takers a formula shaped like P x (1 - P), and resting maker orders usually pay nothing.
This comparison reflects each platform’s published documents as of November 11, 2026. It is not legal or financial advice.
How do Kalshi, Polymarket and Polymarket US compare?
| Kalshi | Polymarket (international) | Polymarket US | |
|---|---|---|---|
| Regulator | CFTC (exchange); clears through affiliate Kalshi Klear | Crypto-based; blocks US users under a 2022 CFTC settlement | CFTC (exchange and clearinghouse) |
| Who can join | 18+; US and many other countries | Users outside the jurisdictions on its geoblock list | US residents except Nevada (no Michigan sports); 18+, higher in 3 states |
| Collateral | US dollars | pUSD on Polygon, backed by USDC | US dollars |
| Taker fee | 0.07 x C x P x (1 - P) | 0 to 0.07 x C x P x (1 - P) by category | 0.0695 to 0.095 x C x P x (1 - P) by volume tier |
| Maker fee | 0 in most markets; 0.0175 rate in listed series | 0, plus rebates | 0 |
| Who decides outcomes | Kalshi, from the source in the contract terms | UMA optimistic oracle (Chainlink for up/down crypto) | The exchange, from listed sources |
| Size limits | Set per contract, e.g. $25,000 accountability level | No order book size limit | $1,000,000 per market buy in the app |
How is each platform regulated?
Kalshi is a designated contract market (DCM) regulated by the CFTC. Its contracts clear through Kalshi Klear, an affiliated clearinghouse.
Polymarket US describes itself as “a fiat-based, US-regulated platform” operating as both a DCM and a derivatives clearing organization. The exchange entity is QCX LLC, which the CFTC designated in July 2025, per CryptoSlate.
Polymarket’s international site is, in Polymarket’s own words, “our international, crypto-based product.” A 2022 CFTC settlement required it to block US users and pay a $1.4 million penalty, Cointelegraph reported.
State-level fights over sports contracts are covered in our guide to whether prediction markets are legal in the US.
Who can use each platform?
- Kalshi: users must be 18 or older and pass document verification if asked. Kalshi accepts users from many countries, with restricted jurisdictions listed in its Member Agreement.
- Polymarket US: open to US residents in every state except Nevada, with no sports contracts in Michigan, as of November 10, 2026. The minimum age is 18, or 19 in Alabama and Nebraska and 21 in Mississippi (CryptoSlate). Sign-up asks for a Social Security number.
- Polymarket (international): its geoblock list fully blocks OFAC-sanctioned places and sets close-only status, where users can exit but not open positions, for countries including the United States, United Kingdom, France, Germany, Australia, Singapore and four Canadian provinces.
What fees does each platform charge?
Kalshi (fee schedule effective July 7, 2026):
- Taker: fees = round up(M x 0.07 x C x P x (1 - P)), where C is contracts, P is price in dollars and the multiplier M defaults to 1.
- Maker: fees = round up(M x 0.0175 x C x P x (1 - P)), with M defaulting to 0, so most resting orders pay nothing.
- No settlement or membership fee. ACH deposits and withdrawals are free; card deposits carry up to 2%.
Kalshi’s fee page lists 160 series with non-standard fees. Many add maker fees, and most combos charge makers 50% of the taker fee. The NFL game series is set to “quadratic_with_maker_fees.”
Polymarket international (fees): fee = C x feeRate x p x (1 - p), and “Makers are never charged fees.” Taker rates are 0.07 for crypto; 0.05 for sports, economics, culture, weather and other; 0.04 for politics, finance, tech and mentions; and 0 for geopolitics. Taker fees fund daily maker rebates of 15% to 25% by category.
Polymarket US (fees): Fee = Θ x C x p x (1 - p), where Θ depends on trailing 30-day taker volume:
| Taker tier | 30-day taker volume | Θ |
|---|---|---|
| 1 | Under $10,000 | 0.095 |
| 2 | $10,000 to $50,000 | 0.085 |
| 3 | $50,000 to $250,000 | 0.075 |
| 4 | $250,000 or more | 0.0695 |
New accounts pay 0.0695 for their first seven days regardless of volume. Maker fills on standard trades pay no fee; rebates start at $10 million of maker volume. Fees round to the nearest cent. Earlier reports, including our odds guide, gave a single 0.0695 rate. The fee page now shows the tiered table, with its standard trading section marked effective October 28, 2026.
Worked example: 200 YES contracts at 40¢ on a football game
Each formula uses C = 200 and P x (1 - P) = 0.40 x 0.60 = 0.24. The contracts cost $80.00 before fees and pay $200.00 if YES wins.
| Venue and order type | Fee | Total cost | Break-even | Profit if YES |
|---|---|---|---|---|
| Kalshi, taker (0.07) | $3.36 | $83.36 | 41.68% | $116.64 |
| Kalshi, maker in NFL game series (0.0175) | $0.84 | $80.84 | 40.42% | $119.16 |
| Polymarket, taker, sports (0.05) | $2.40 | $82.40 | 41.20% | $117.60 |
| Polymarket US, taker, Tier 1 (0.095) | $4.56 | $84.56 | 42.28% | $115.44 |
| Polymarket US, taker, first 7 days (0.0695) | $3.34 | $83.34 | 41.67% | $116.66 |
| Any venue, maker with no maker fee | $0.00 | $80.00 | 40.00% | $120.00 |
Kalshi taker fee: 0.07 x 200 x 0.24 = $3.36. Polymarket US Tier 1: 0.095 x 200 x 0.24 = $4.56. If NO wins, the buyer loses the full total cost. The gap between the cheapest and most expensive taker route is $2.16, or 1.08 points of break-even. Our break-even calculator runs the same math for other prices.
How do markets resolve on each platform?
Kalshi. Each contract’s terms name a source agency; for NFL games the contract terms list the league first, then ESPN, CBS Sports and others. The process:
- After the market closes, Kalshi determines the outcome from that source, which takes one hour to more than twelve hours.
- A settlement timer runs, during which the result may be disputed and re-determined.
- Before settlement, Kalshi may, at its discretion, send the market to its Outcome Review Committee, which must decide within 24 hours; its decisions “are final” (Rulebook Rule 7.1).
Traders can also use a Request to Settle button that sends a market to Kalshi’s markets team.
Polymarket international uses the UMA optimistic oracle:
- Anyone proposes an outcome and posts a bond, typically $750.
- A 2-hour challenge period follows. With no dispute, the market resolves.
- A disputer posts a matching bond, which triggers a second proposal.
- A second dispute sends the question to UMA token holders after a 24 to 48 hour debate, with voting taking about 48 hours.
Undisputed markets resolve about 2 hours after the proposal; disputed ones take 4 to 6 days. A vote can return “Unknown/50-50,” which pays $0.50 per share. Up/down crypto markets skip UMA and resolve from a Chainlink price feed.
Polymarket US has the exchange determine outcomes from the sources in each market’s rules, and all resolutions are final under its rulebook. CryptoSlate reports that senior officers can reverse a result for obvious error and that claims go to arbitration in New York.
How do deposits and collateral work?
All three are fully collateralized. On Kalshi, a YES buyer and a NO buyer together put up $1. On Polymarket, $1 of pUSD creates one YES and one NO share. On Polymarket US, sellers post $1.00 per contract.
- Kalshi: debit card ($10 minimum, up to 2% fee), free ACH for US users that settles within 5 business days, free wires of $1,000 or more, crypto, PayPal and Venmo. International users can use debit cards, wires and crypto.
- Polymarket: collateral is pUSD, an ERC-20 token on Polygon backed by USDC. Assets sent from Ethereum, Solana, Bitcoin, Tron and other chains are converted to pUSD automatically. Polymarket charges no fee to deposit or withdraw USDC, though intermediaries may.
- Polymarket US: debit card, ACH, Apple Pay, PayPal, Venmo, USDC on iPhone and wire ($5,000 minimum). Card and ACH deposits are capped at $50,000 a day. Withdrawals are free once a deposit clears, typically 3 to 4 business days.
What are the position and order limits?
- Kalshi sets limits in each contract’s terms, defined as maximum loss. An NFL game contract has a position accountability level of $25,000 per strike, per member; above it, Kalshi can demand information and order the position reduced (Rule 5.18). The presidential winner contract has a hard limit of $7,000,000 per strike for individuals.
- Polymarket says its order book has “no trading size limits”, while warning that large orders can move the price.
- Polymarket US caps a single market buy in the app or on the web at $1,000,000.
What kinds of markets does each list?
- Kalshi: yes/no contracts grouped into events, plus combos priced by request for quote, where the payout is the product of each leg’s value.
- Polymarket: binary markets grouped into events, negative-risk multi-outcome events where a NO in one outcome converts to a YES in every other, up/down crypto markets and combos.
- Polymarket US: binary, multi-outcome and range contracts plus combos of 2 to 10 legs (CryptoSlate), across sports, politics, crypto, economics, weather, tech and culture.
When comparing them, check eligibility first, then the funding route, the fee at your price and category, and the resolution rules of the specific market. For why the maker column matters, see our perspective piece on starting as a maker.