How often do Kalshi and Polymarket disagree on price?
Most of the time they agree within a cent. On average the same contract trades 1.9¢ apart, and about one hour in ten the gap is 5¢ or more.
We track every event listed on both exchanges and record the price of each matched outcome once an hour. This page summarizes 12,923 paired observations across 1,332 contracts over 7 days (2026-11-02 to 2026-11-09). It updates daily.
Key numbers
| Average absolute gap | 1.94¢ per $1 contract |
| Within 1¢ | 65.4% of observations |
| Within 2¢ | 79.2% |
| 3¢ or more | 20.8% |
| 5¢ or more | 9.7% |
| 10¢ or more | 4.6% |
Distribution of gaps
By category
| Category | Contracts | Observations | Avg gap | 5¢+ |
|---|---|---|---|---|
| Sports & esports | 1157 | 6,782 | 1.41¢ | 7.5% |
| Politics & elections | 125 | 4,756 | 2.53¢ | 11.1% |
| Other (culture, world events, science) | 36 | 1,175 | 2.64¢ | 15.1% |
| Economy, markets & crypto | 14 | 210 | 2.08¢ | 17.1% |
Most persistent gaps
Contracts observed for at least 24 hours with meaningful volume, ranked by average gap. Large, lasting gaps usually mean the two exchanges word the contract differently, so read both rulebooks before treating a gap as an opportunity (see arbitrage guide).
| Contract | Hours | Avg gap | Max gap |
|---|---|---|---|
| Prime Minister of Israel after the next election? — Benjamin Netanyahu | 157 | 14.5¢ | 20¢ |
| Vitesse Arnhem vs. De Graafschap — De Graafschap | 24 | 14.2¢ | 16¢ |
| Next James Bond actor? — Robert Pattinson | 32 | 12.4¢ | 20¢ |
| Prime Minister of Israel after the next election? — Gadi Eizenkot | 166 | 11.0¢ | 20¢ |
| Next James Bond actor? — Josh O'Connor | 68 | 9.1¢ | 18¢ |
| Next James Bond actor? — Callum Turner | 68 | 7.1¢ | 19¢ |
| Who will leave Trump Administration before 2027? — Marco Rubio | 29 | 5.7¢ | 15¢ |
| Anthropic IPO by __? — November 16, 2026 | 65 | 4.8¢ | 9¢ |
| Prime Minister of Israel after the next election? — Avigdor Lieberman | 60 | 4.1¢ | 11¢ |
| Next Press Secretary? — Scott Jennings | 37 | 3.9¢ | 18¢ |
How to read this
A gap is the absolute difference between the two exchanges' mid prices for the same outcome, in cents per $1 contract. Mid prices are not fills: spreads, fees and depth decide what you would actually pay. Contracts priced below 5¢ or above 95¢ are excluded because rounding dominates there. Matching is automatic and occasionally pairs contracts whose rules differ in small ways. Full details are on the methodology page.
Use this data
Download the per-contract summary as CSV. Licensed CC BY 4.0: cite "Zlotex (zlotex.com)" with a link. Live prices for every matched event are on the comparison page.