Polymarket vs. Kalshi
Compare markets
See where the two biggest prediction markets disagree. Pick any two markets, or start from the biggest gaps below: prices, volume, history and the resolution rules, side by side.
Will Pedro Sánchez become Prime Minister of Spain following the next Spanish general election?
Vol $1.7K today · $9.6K total
Will Yolanda Díaz be the next Prime Minister of Spain?
Vol $285 today · $170.7K total
Kalshi is 20 points higher than Polymarket (21% vs 0%). Kalshi trades about 6× more volume today, so its price has more money behind it. They resolve on different dates (Aug 22 vs Apr 1), so they may not be exactly the same bet.
History starts when we first saw each market, so a newly added market has a short line.
| Kalshi | Polymarket | |
|---|---|---|
| Probability (Yes) | 21% | 0% |
| Change (24h) | +2.5 pt | +0.1 pt |
| Volume today | $1.7K | $285 |
| Total volume | $9.6K | $170.7K |
| Liquidity | — | $86.5K |
| Open interest | $6.8K | — |
| Resolves | 22mo | 18mo |
| Tracked for | 14 days | 14 days |
Resolution rules: read both before trusting a gap
Kalshi
If Pedro Sánchez becomes Prime Minister of Spain as a result of government formation following the next Spanish general election and meets all constitutional requirements before Aug 22, 2028, then the market resolves to Yes.
Polymarket
This market will resolve to the next individual who officially assumes the office of Prime Minister of Spain by March 31, 2028, 11:59 PM ET. To count for resolution, the individual must receive a vote of confidence from the Congress of Deputies and be formally sworn-in, resulting in the official formation of a new government. Any interim or caretaker Prime Minister who does not receive a parliamentary vote of confidence will not count toward the resolution of this market. If no such Prime Minister takes office by March 31, 2028, 11:59 PM ET, this market will resolve to “Other”. The primary resolution source for this market will be official information from the Government of Spain; however, a consensus of credible reporting may also be used.
Share this comparison
Informational only — not financial advice. Odds are mirrored from each platform and may lag the live order book.