Kalshi vs Polymarket — NBA Price Gaps
Kalshi and Polymarket both price NBA games — and they don’t always agree. Below are the live gaps between the two exchanges on tonight’s slate, with a de-vigged sportsbook line shown so you can see how much wider the book sits.
Live NBA Price Gaps: Kalshi vs Polymarket
Updated May 30, 11:30 PM ETWhere Kalshi and Polymarket price the same game differently right now. Two exchanges disagreeing on the same outcome is a genuine cross-exchange gap — unlike a sportsbook line, which bakes in vig (the house edge). The book's implied price is shown for reference so you can see how much wider it sits.
Gaps are the difference in implied probability between the two exchanges on the same game, ranked by symmetric KL divergence. Polymarket prices come from the latest hourly snapshot; Kalshi prices are live. Sportsbook prices are de-vigged for a fair comparison. Informational only — verify resolution terms before trading.
How we compute the gap
For each NBAgame listed on both exchanges, we take Kalshi's live implied probability and Polymarket's latest snapshot probability for the same team, then measure how far apart they are. Games are ranked by symmetric KL divergence — a measure of how much the two price distributions disagree — and we surface the biggest gaps first. A “gap” here is the difference in implied probability between the two exchanges, in percentage points.
A cross-exchange gap is not the same as a sportsbook edge. Two exchanges disagreeing is a genuine signal; a sportsbook line sitting wider is mostly vig — the house margin baked into both sides. That's why we lead with the Kalshi–Polymarket comparison and show the book only for reference. Informational only — always verify resolution terms and liquidity before taking a position.
NBA: Kalshi vs Polymarket FAQ
Is Kalshi or Polymarket cheaper for NBA?
It changes game by game. Two efficient exchanges rarely sit far apart, but when they do, the cheaper venue for a given team is whichever prices that outcome lower. The live table above flags the cheaper exchange on each game. Unlike a sportsbook, neither exchange bakes in vig, so the gap you see is the real cross-exchange difference.
Can you arbitrage Kalshi against Polymarket on NBA games?
When the two exchanges price the same outcome differently enough, the gap is a genuine cross-exchange signal. Polymarket is geoblocked for US traders, so most US readers trade the Kalshi side; the gap still tells you which exchange the market consensus favors. Always verify resolution terms and liquidity before taking a position.
How current are the NBA prices?
Kalshi prices are live. Polymarket prices come from the latest hourly market snapshot. The table refreshes on a short interval and stamps when it was last updated.
Why does the sportsbook price look wider?
A sportsbook line includes vig — the house edge baked into the two sides. We de-vig the book price for a fair comparison, but it still tends to sit wider than two competing exchanges, which is exactly why a Kalshi–Polymarket gap is a sharper signal than a book–exchange gap.