MargusKalshi and Polymarket US are the two US-regulated prediction market exchanges most sports fans compare. Both sell $1 event contracts, both list NFL, NBA and soccer games, and both price them through an order book rather than a bookmaker. The useful question is not which brand is better, but which one has the better price for the game you care about today.
Affiliate disclosure: Margus may earn compensation from some outbound operator links. Commercial relationships never change which stored price ranks as best. The fee-schedule links in this guide are direct informational sources.
Key takeaways
- Same basic product. Both trade binary contracts that pay $1 if the outcome happens, so prices read as implied probabilities.
- Different fee designs. Polymarket US publishes a formula fee that peaks at 50 cents; Kalshi charges a transaction fee on expected earnings and some markets differ.
- Both are on the CFTC's list of designated contract markets. Eligibility and state-level treatment still vary, so check current status.
- The better price changes game by game. Liquidity, fees and timing move the edge around.
- Rules decide comparability. Two similar-looking contracts can settle differently.
Kalshi vs Polymarket at a glance
Business model
- Kalshi: US exchange for event contracts; earns from trading fees.
- Polymarket US: US exchange operated by QCX LLC; earns from trading fees.
Regulation
- Kalshi: listed by the CFTC as a designated contract market (CFTC list).
- Polymarket US: QCX LLC d/b/a Polymarket US listed by the CFTC as a designated contract market (same source).
Contract and price
- Kalshi: Yes and No contracts priced in cents, settling at $1 or $0 under each market's rules.
- Polymarket US: contracts priced from $0.01 to $0.99, settling at $1 or $0 under each market's rules.
Fees
- Kalshi: transaction fee based on expected earnings; some markets have different fees and some have maker fees; no fee to cancel a resting order (Kalshi fees).
- Polymarket US: standard taker fee = 0.0695 × contracts × price × (1 − price); maker rebates by volume tier; no fee on cancelled orders (Polymarket US fees).
Sports coverage
- Both: game markets on major US leagues and football (soccer), with fewer props per game than a large sportsbook. Coverage changes by season, so check each operator's catalogue.
Best for
- Kalshi may fit: readers who want to compare sports contracts alongside a broader catalogue of event markets, subject to current eligibility and market availability.
- Polymarket US may fit: readers who want to estimate the standard taker fee from a published formula, while accounting for market-specific coefficients and rebates.
- Either may fit: only when it offers the better fee-adjusted executable price, enough size and settlement rules that match the intended outcome.
What both platforms have in common
Kalshi and Polymarket US work the same way at the core. Participants post buy and sell orders, the exchange matches them, and the exchange earns from fees rather than from the result. Neither is a sportsbook: no one is setting a price and taking the other side with a built-in margin.
Because both pay $1 on the winning side, prices on both venues convert into probability the same way. A 62 cent contract implies about 62%, which is decimal odds of about 1.61, American about -163 or fractional about 8/13. Our guides on reading odds and implied probability cover the conversions.
Fees compared
Fees are where the two differ most, and they matter because they are charged on top of the price.
Polymarket US publishes a formula. Standard taker fees are 0.0695 × C × p × (1 − p), so a 100-contract taker trade costs $1.74 at 50 cents and $0.63 at 10 or 90 cents, according to its fee table. Makers whose resting orders fill can receive rebates by monthly volume tier, and some market types use different coefficients.
Kalshi says it charges a transaction fee on the expected earnings on a contract, publishes a full fee schedule, notes that fees can differ for special events and major championships, and charges maker fees in some markets. The exact cost depends on the market, so read the schedule for the contract you are looking at.
The practical rule: convert both prices to probability, add each venue's fee, then compare. A one-cent price advantage can disappear once fees are included, especially on games priced near 50/50. For sportsbook prices the cost is already inside the odds as vig, which is why you need to put everything on the same footing.
Pricing and liquidity
Two exchanges listing the same game will rarely show identical prices. Different users, different market makers and different update speeds all create gaps, and gaps are opportunities for anyone who line shops.
Liquidity is the other half. The displayed price only applies to the size sitting at that price. A deep market lets you trade a meaningful amount close to the quoted number; a thin one may move against you after a few contracts. Before acting on a better price, check how much is available at it and how wide the spread between the best buy and sell orders is.
Regulation and availability
Both Kalshi and QCX LLC (d/b/a Polymarket US) appear on the CFTC's list of designated contract markets. That federal status sits alongside an unsettled debate in several US states about how sports event contracts should be treated, so the picture can change. Check the current status before relying on access in your state.
For readers in the UK and Europe, remember that Margus tracks the US-regulated venues. Access to any product depends on each operator's eligibility rules and your local law, and Margus does not confirm eligibility anywhere.
Settlement rules: the hidden difference
Contract titles can look the same and still settle differently. Before comparing, check:
- Overtime and extra time. Does the contract include overtime (NFL, NBA) or extra time (cup football)?
- Draws. In football (soccer), is it a three-way result, or a "team to win" contract where a draw means No?
- Postponements and abandonments. What happens if the game moves or is not completed?
- Resolution source. Which official source decides the result?
Margus only compares outcomes it can map to the same event and result, but the contract text always controls settlement.
Which is better for football and US sports?
For US sports, moneyline-style game markets on both exchanges usually map cleanly, so NFL and NBA games are the best place to compare all three: Kalshi, Polymarket US and the sportsbooks.
For football (soccer), the draw makes comparisons harder. Sportsbooks price home, draw and away. An exchange "team to win" contract folds the draw into No. Compare only matching outcomes, and use our soccer odds to see the full 1X2 market alongside.
Overall, there is no permanent winner. The better venue is the one with the better fee-adjusted price, enough depth for your size and rules that match the outcome you want.
How to compare them with Margus
- Open the Kalshi page and the Polymarket page. Each shows a seven-day table of that venue's stored price against the best stored sportsbook price.
- Find the same game and outcome on both tables and compare implied probabilities.
- Add each venue's fee, then check the full sportsbook market on /odds, NFL odds or soccer odds.
- Confirm the live price, size and contract rules with the operator before acting.
Our methodology explains how Margus maps events and selects best prices. We are building a long-run record of how often each venue had the better price; it will appear here once there is enough data to be meaningful. For background on the two models, read prediction markets vs sportsbooks, or go back to the prediction markets hub.
Play responsibly
Trading event contracts and betting both carry risk. Set limits, take breaks and never stake money you cannot afford to lose. Support is listed on our responsible gaming page.
Frequently asked questions
Which is better, Kalshi or Polymarket?
Neither is better for every market. The better venue for a given game is the one with the better price after fees, enough liquidity for your size, and contract rules that match what you want. That changes from game to game, which is why comparing prices matters.
Which has lower fees, Kalshi or Polymarket?
It depends on the market and price. Polymarket US publishes a formula-based taker fee that peaks at 50 cents; Kalshi charges a transaction fee based on expected earnings and some markets have different or maker fees. Check both live fee schedules for the specific market before comparing.
Are Kalshi and Polymarket both regulated?
The CFTC lists both Kalshi and QCX LLC (d/b/a Polymarket US) as designated contract markets. State-level treatment of sports event contracts has been contested and can change, so check the current status where you live.
Can I use Kalshi or Polymarket in the UK?
Both venues Margus tracks are US-regulated exchanges, and access depends on each operator's eligibility rules and your local law. Margus does not confirm eligibility for any location.
Can Kalshi and Polymarket prices be compared directly?
Only when both contracts resolve on the same outcome under equivalent rules. Check how each contract treats overtime, draws, postponements and the official source before treating two prices as comparable.
Does Margus favour either operator?
No. Margus ranks stored, mapped prices only. It does not take bets, and commercial relationships do not change which price is shown as best.
How often does Kalshi beat Polymarket on price?
We do not publish a figure yet. Margus plans to track how often each venue had the better stored price over time; until that data is live, use the comparison tables on each operator page to check individual games.