Home › Polymarket vs Kalshi › Price gaps
Updated November 9, 2026 at 02:08 UTC · refreshed twice a day · free CSV and JSON below
Across 71 outcomes priced on both Polymarket and Kalshi on November 9, 2026, the two exchanges differ by 1.0 points on average (median 1.0); 90% are within 2 points and 100% within 5. Among the 22 competitive outcomes (both prices between 10% and 90%) the average gap is 1.2 points. The widest: Will Anthropic or OpenAI IPO first, OpenAI (Polymarket 2.2%, Kalshi 6.5%).
| Category | Outcomes | Average gap (pts) | Median gap | Within 2 pts |
|---|---|---|---|---|
| Economy and business | 3 | 2.8 | 2.8 | 33% |
| Elections | 2 | 2.0 | 2.0 | 100% |
| Fed | 20 | 1.1 | 1.0 | 85% |
| Governor races | 2 | 0.3 | 0.3 | 100% |
| Senate races | 4 | 0.7 | 0.8 | 100% |
| Sports | 40 | 0.8 | 0.9 | 95% |
| Market | Outcome | Polymarket | Kalshi | Gap (pts) |
|---|---|---|---|---|
| Will Anthropic or OpenAI IPO first | OpenAI | 2.2% | 6.5% | -4.2 |
| Fed decision, April meeting | Cut 25 bp | 9.0% | 12.5% | -3.5 |
| Stanley Cup 2027 | Carolina Hurricanes | 11.5% | 14.5% | -3.0 |
| Will Anthropic or OpenAI IPO first | Anthropic | 97.8% | 95% | +2.8 |
| Fed decision, March 16–17, 2027 | No change | 53% | 55.5% | -2.5 |
| Fed decision, April meeting | No change | 65% | 62.5% | +2.5 |
| NBA champion 2027 | Golden State Warriors | 2.4% | 4.5% | -2.1 |
| Which party wins the 2028 presidential election | Democrats | 67.5% | 65.5% | +2.0 |
| Fed decision, January 26–27, 2027 | No change | 77.5% | 75.5% | +2.0 |
| Stanley Cup 2027 | Florida Panthers | 5.5% | 7.5% | -2.0 |
| Champions League 2027 winner | Barcelona | 23.5% | 21.5% | +2.0 |
| Which party wins the 2028 presidential election | Republicans | 32.5% | 34.5% | -2.0 |
Gap = Polymarket minus Kalshi in percentage points, before fees. Senate and governor races compare each party's candidate; Fed meetings compare the same decision outcome.
More: Polymarket vs Kalshi, event by event · Senate forecast with Kalshi prices · Fed rate odds on both · Arbitrage calculator
Quoting this study in an article, a paper or a newsletter? Copy this citation and keep the date, because prices move. Tips: how to cite Polymarket odds.
Polymarket View, “How close are Polymarket and Kalshi odds?”, November 9, 2026, https://polymarkettrader.com/polymarket-vs-kalshi/price-gaps/ (data: Polymarket, CC BY 4.0).
Across 71 outcomes priced on both Polymarket and Kalshi on November 9, 2026, the two exchanges differ by 1.0 points on average (median 1.0); 90% are within 2 points and 100% within 5. Among the 22 competitive outcomes (both prices between 10% and 90%) the average gap is 1.2 points. The widest: Will Anthropic or OpenAI IPO first, OpenAI (Polymarket 2.2%, Kalshi 6.5%).
They are separate exchanges with their own traders, fees, rules and settlement sources, and money cannot move freely between them, so the same event can trade at slightly different prices.
Only if the gap is larger than both exchanges' fees and the two contracts settle on exactly the same rules. Check with the arbitrage calculator: polymarkettrader.com/tools/polymarket-arbitrage-calculator/.
Polymarket prices are the outcome prices Polymarket publishes; Kalshi prices are the midpoint of its best bid and ask (the last trade when the book is one-sided), both read on the same run. The gap is Polymarket minus Kalshi in percentage points, before fees.
Data: CSV · JSON (CC BY 4.0, attribution: PolymarketTrader.com). Polymarket View is independent and not affiliated with Polymarket or Kalshi. Educational information, not financial advice.