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.
SCOTUS accepts sports event contract case by December 31, 2026?
Vol $77.2K today · $165.8K total
Will the Federal Reserve hike rates by December 31, 2026?
Vol $4.9K today · $130.3K total
Kalshi is 53 points higher than Polymarket (83% vs 30%). Polymarket trades about 15.9× more volume today, so its price has more money behind it.
History starts when we first saw each market, so a newly added market has a short line.
| Polymarket | Kalshi | |
|---|---|---|
| Probability (Yes) | 30% | 83% |
| Change (24h) | -9.0 pt | +4.5 pt |
| Volume today | $77.2K | $4.9K |
| Total volume | $165.8K | $130.3K |
| Liquidity | $31.1K | — |
| Open interest | — | $72K |
| Resolves | 64d | 64d |
| Tracked for | 14 days | 19 days |
Resolution rules: read both before trusting a gap
Polymarket
This market will resolve to "Yes" if the Supreme Court of the United States grants certiorari in a case explicitly concerning the legality, regulation, or jurisdictional authority over sports event contracts by December 31, 2026, 11:59 PM ET. Otherwise, this market will resolve to "No." A case qualifies if it addresses at least one of the following: (1) whether contracts based on sporting event outcomes constitute regulated derivatives under the Commodity Exchange Act; (2) whether federal regulation via the Commodity Futures Trading Commission preempts state-level gambling laws as applied to such contracts; or (3) whether sports event contracts offered by federally licensed markets may legally be offered, restricted, or prohibited by federal or state authorities. The certiorari grant must be publicly confirmed via the official SCOTUS docket or orders list, and verifiable through credible legal reporting or the Supreme Court’s official website. The case does not need to be heard, scheduled, or decided to qualify. The resolution source will be a consensus census of credible reporting.
Kalshi
If the Federal Reserve announces an increase in the target range or target level for the federal funds rate after market Issuance and on or before Dec 31, 2026, 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.