Kalshi vs Polymarket: Fees, Settlement and Liquidity Compared
A side‑by‑side look at how the two main U.S.-facing prediction platforms are structured, how they charge, and how contracts pay out.
By Top Prediction Markets EditorialReviewed October 29, 20265 min read
Answer first
Kalshi is built as a regulated exchange with exchange-style settlement and order routing; Polymarket has used automated market makers and liquidity pools with a different fee and settlement flow. The key differences are how fees are collected (exchange fees vs. AMM/market fees), how contracts resolve and where liquidity comes from. Check each platform’s terms and your location before trading.
The main structural contrast in one paragraph
Kalshi operates as a centralized, regulated exchange where events are listed and traded like exchange-traded contracts under an order-book model and clearing process. Polymarket has historically used decentralized market-making models (automated market makers, or AMMs) with liquidity pools; prices there are set algorithmically and by liquidity providers rather than by a visible order book.
In simple terms: Kalshi routes trades through an exchange order book model under regulatory oversight; Polymarket routes trades into liquidity pools or AMMs where prices depend on pool depth and curve parameters. The core consequence for a user is predictability: exchange models give visible order books and standard order types; AMM models give continuous prices that vary with pool liquidity.
Direct comparison: fees, settlement, liquidity and access
Below is a direct, side-by-side look at the practical features most traders compare. This lists structural differences rather than promotional rates; always check current platform disclosures for up-to-the-minute fees.
| Feature | Kalshi | Polymarket |
|---|---|---|
| Structure | Centralized exchange model (regulated entity listed as a contract market) | AMM/liquidity-pool model with platform market mechanics (web-native) |
| Fee charging method | Exchange-style fees (trading fees, possible clearing/router fees) collected by the platform or clearinghouse | Platform fee + liquidity-provider fees embedded in price; fees may be taken on trade or at settlement depending on market design |
| How contracts settle | Settlement on event resolution with exchange-managed clearing and payout to account balances | Settlement on resolution; payouts come from the market’s liquidity pool or designated reserves; settlement mechanism can be on-chain or off-chain depending on market |
| Liquidity source | Market participants placing orders, professional market makers, and exchange order book depth | Liquidity pools, AMMs and liquidity providers who set prices according to bonding curves; depth varies by pool size |
| Market coverage | Curated, exchange-listed event contracts (calendar-driven listing cadence) | Broad and user-created market coverage; many topical or short-lived markets possible |
| Access & identity requirements | Typically requires identity verification, KYC, and account approval | Often requires fewer formalities for browsing; participation rules depend on jurisdiction and platform rules |
The key thing to know: fees and liquidity are not just line items — they determine how easy and expensive it is to enter or exit a position and how close the displayed price is to a fair probability.
Where fees show up and what to watch for
Exchange-style fees (Kalshi): fees often look like per-trade fees or percentage fees collected by the exchange and/or clearing members. Fees may be charged on trades or when positions settle. You may also encounter spread costs if you trade against an order book with thin depth.
AMM or pool fees (Polymarket): the visible price you pay includes the AMM curve and any protocol fee. Liquidity providers implicitly charge for the risk they take by shifting the price curve; the platform can also collect a percentage of each trade. That means you don’t always see a separate “fee line item” — the cost can be embedded in price.
Common mistake: equating a low visible fee rate with low total cost. On AMM markets, shallow pools can move prices a lot for moderate-sized trades, making the effective cost higher.
Settlement mechanics and why timing and criteria matter
Settlement is how a contract becomes worth $1 or $0 at resolution, and differences in settlement processes affect when you get funds and how ambiguous outcomes are handled.
Kalshi-style settlement: resolution follows published event rules and clearing-house processes. Payouts are credited to your account balances under the exchange’s settlement timetable. Because Kalshi operates as an exchange, disputes and resolution criteria are administered under exchange rules.
Polymarket-style settlement: resolution depends on the market’s rules and whether resolution is automated (oracle feeds, smart contracts) or managed off-chain. Some markets rely on third-party oracles to post outcomes, others use a small resolution panel. Timelines and dispute policies vary.
Effect on users: settlement timing affects when you can withdraw funds. Resolution criteria affect how ambiguous events are handled, so read the market terms for each contract.
Worked example: buying a Yes contract
If a Yes contract costs 62¢ and pays $1 if the event happens, buying one contract costs $0.62. If the event happens, the contract pays $1, so the gain before fees is $0.38. If the event does not happen, the contract expires at $0, so the loss is $0.62.
Now imagine two fee patterns to see how structure changes outcomes:
-
Exchange fee taken on trade: if the platform charges a fee when you buy (for example, a percentage of the $0.62 trade), your initial cash outlay is $0.62 plus the fee, reducing net return if the event resolves True.
-
Pool/AMM fee embedded in price: the 62¢ price already reflects the AMM curve and any protocol fees. You may not see a separate fee, but the price can be higher because the pool requires compensation for providing liquidity.
This arithmetic shows the practical difference: where the fee appears—added at trade time or hidden in the price—and how large a trade will move the market.
Liquidity patterns and the types of markets you’ll find
If you want deep, high-volume markets, exchange-listed events with professional market makers typically provide tighter spreads and more stable prices. Exchanges can handle larger blocks if there are active counterparties on the order book.
If you want a wide range of niche or rapidly-created markets, AMM/pool platforms usually offer more variety. Expect Polymarket-style platforms to host many topical, pop-culture, or very-short-term events — coverage is broader but liquidity per market varies.
When liquidity matters: large trades on AMMs can shift the price a lot unless the pool is deep. On exchanges, order books can allow traders to see depth and work around thin liquidity using limit orders and order types.
Which fits you: plain guidance
Choose a regulated exchange-style platform if you prioritize standardized settlement, visible order books, formal regulatory oversight, and the predictability of order types and clearing procedures.
Choose an AMM/liquidity-pool platform if you want access to many unique, user-created or short-lived markets and accept that prices and effective fees depend on pool depth and curve mechanics.
Always check identity, jurisdiction and withdrawal rules before you fund an account.
Keep reading
Frequently asked questions
Do Kalshi and Polymarket use the same fee model?
No. Kalshi follows an exchange-style fee model with explicit trading and clearing fees; Polymarket-style platforms embed fees in AMM pricing and may add platform fees. Check each market’s fee disclosure.
How long does settlement take after an event resolves?
Settlement timing varies by platform and market. Exchanges often have set settlement windows; AMM-style markets settle according to the market’s resolution rules and oracle timing. Check the market’s rules before trading.
Are both platforms available everywhere?
Availability depends on your jurisdiction and the platform’s policies. Each platform publishes its geographic and eligibility rules — check them before signing up.
Are prediction markets legal in the U.S.?
Rules vary by location and platform. See our dedicated guide on whether prediction markets are legal in the US.
What determines price movement on each platform?
On an exchange, price moves because orders hit the order book; on AMM platforms, price moves according to the liquidity curve and pool depth, which changes with each trade.
Related guides
Beginner Guide
How to Read Prediction Market Prices
Learn what a prediction market price represents, how to read it as an implied probability, and what practical things (like spreads and liquidity) change how you should use that number.
Beginner Guide
How Do Prediction Markets Work?
Prediction markets let people buy and sell contracts that pay out if an event happens. Prices reflect the market’s collective forecast and update as new information arrives.
Beginner Guide
What Are Prediction Markets?
Prediction markets are markets where people buy contracts that pay out if a future event happens. Prices reflect the crowd’s best estimate of the chance an event will occur.