Kalshi vs Polymarket for NBA games
Kalshi and Polymarket both list every NBA game as a contract that pays $1 if a team wins. They often price the same game a few cents apart. Here is how the two venues differ on fees, settlement and liquidity, plus the live gaps between them tonight.
| Kalshi | Polymarket | |
|---|---|---|
| Regulation | CFTC-regulated designated contract market | US app operating under a CFTC-registered exchange; international site separate |
| NBA markets | Moneyline, spread and total for every game, plus futures | Moneyline, spread and total for most games, plus futures |
| Taker fee | About 7% × price × (1 − price) per contract, rounded up to the cent | Market-specific rate × price × (1 − price); many markets are fee-free |
| Price display | Cents per $1 contract | Cents per $1 share |
| Settlement | Official league result, overtime included | Official result per market rules; read each market’s resolution text |
Tonight’s biggest Kalshi–Polymarket gaps
Loading live NBA prices…
Fees decide which gap is real
A 3-cent difference between venues can shrink to almost nothing after fees. Kalshi charges takers roughly 7% of price × (1 − price) per contract, which peaks at 1.75¢ on a 50¢ contract. Polymarket uses a market-specific rate on the same curve, and many of its markets charge no taker fee at all.
Courtside subtracts the modeled fee for each venue before it reports an edge, so the number on the board is what is left after costs. Use the fee calculator to check a specific order size.
Liquidity and price movement
Both venues show an order book, but the best price may only be available for a few hundred dollars. Larger orders walk up the book and pay more. Courtside shows how much size sits at the best ask and, for Pro members, every visible level.
Prices on both venues react to injury news and sportsbook line moves. They do not always move together, which is why gaps open up. Most close within minutes.
Settlement rules can differ
Two contracts on the same game are not always identical. Overtime handling, postponement rules and the data source used for the result can differ. Courtside labels each comparison as exact, basis risk or incompatible, and leaves incompatible pairs out of its edge numbers.
- Exact: both contracts settle the same way.
- Basis risk: small differences, such as the result source or deadline.
- Incompatible: a rule difference can change who gets paid.
Common questions
Is Kalshi or Polymarket cheaper for NBA games?
It changes game by game and minute by minute. Fees favor Polymarket on fee-free markets, while Kalshi often has deeper books on marquee games. Courtside compares both after fees on every game.
Can I use both Kalshi and Polymarket?
Yes, where each venue is available to you. Many traders hold accounts on both and buy wherever the price is better after fees.
Do Kalshi and Polymarket NBA contracts include overtime?
Game-winner contracts on both venues normally settle on the final result including overtime, but always read the specific market’s rules. Courtside flags contracts whose rules differ.
Why do the two venues show different prices?
They have separate order books and different traders. News reaches them at different speeds, so prices drift apart until someone trades the gap away.