Polymarket vs. Kalshi
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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 Samuel Alito announce his retirement by June 30, 2027?
Vol $1.2K today · $165.6K total
Will Mike Evans announce his retirement before the 2027-28 NFL season?
Vol $413 today · $1.2K total
Kalshi is 2 points higher than Polymarket (55% vs 54%). Polymarket trades about 2.8× more volume today, so its price has more money behind it. They resolve on different dates (Jul 1 vs Sep 30), 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.
| Polymarket | Kalshi | |
|---|---|---|
| Probability (Yes) | 54% | 55% |
| Change (24h) | +0.5 pt | +12.0 pt |
| Volume today | $1.2K | $413 |
| Total volume | $165.6K | $1.2K |
| Liquidity | $51.1K | — |
| Open interest | — | $183 |
| Resolves | 8mo | 11mo |
| Tracked for | 12 hours | 19 days |
Resolution rules: read both before trusting a gap
Polymarket
This market will resolve to "Yes" if Samuel Alito announces that he will retire from his position as Associate Justice of the Supreme Court of the United States by the specified date at 11:59 PM ET. Otherwise, this market will resolve to "No". The announced timing of his retirement may be immediate, at the end of the current Supreme Court term, or at any point in the future. Any qualifying announcement from Alito will count for a "Yes" resolution, regardless of whether the announced retirement goes into effect. The resolution source for this market will be official announcements from Alito or one of his official representatives.
Kalshi
If Mike Evans announces his retirement from the NFL before the 2027-28 NFL season start date, then the market resolves to Yes.
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Informational only — not financial advice. Odds are mirrored from each platform and may lag the live order book.