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 Marco Rubio announce a run for President of the United States before Jun 1, 2027?
Vol $0 today · $0 total
Will Marco Rubio win the 2028 US Presidential Election?
Vol $42.5K today · $13.2M total
Kalshi is 27 points higher than Polymarket (36% vs 9%). They resolve on different dates (Jun 1 vs Nov 8), 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) | 36% | 9% |
| Change (24h) | -3.0 pt | -0.1 pt |
| Volume today | $0 | $42.5K |
| Total volume | $0 | $13.2M |
| Liquidity | — | $237K |
| Open interest | — | — |
| Resolves | 7mo | 25mo |
| Tracked for | 18 days | 21 days |
Resolution rules: read both before trusting a gap
Kalshi
If Marco Rubio has announced that he will run for President of the United States in 2028 before Jun 1, 2027, including running for the nomination of any political party to contest that office, then the market resolves to Yes.
Polymarket
The 2028 US Presidential Election is scheduled to take place on November 7, 2028. This market will resolve to the person who wins the 2028 US Presidential Election. The resolution source for this market is the Associated Press, Fox News, and NBC. This market will resolve once all three sources call the race for the same candidate. If all three sources haven’t called the race for the same candidate by the inauguration date (January 20, 2029) this market will resolve based on who is inaugurated.
Share this comparison
Informational only — not financial advice. Odds are mirrored from each platform and may lag the live order book.