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 the S&P 500 Index be above $10,000 before Dec 31, 2029?
Vol $0 today · $150 total
Kalshi is 65 points higher than Polymarket (65% vs 0%). They resolve on different dates (Dec 31 vs Jan 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) | 65% | 0% |
| Change (24h) | +0.0 pt | -0.1 pt |
| Volume today | $0 | $1K |
| Total volume | $150 | $913.4K |
| Liquidity | — | $120.4K |
| Open interest | $150 | — |
| Resolves | 39mo | 71d |
| Tracked for | 12 days | 12 days |
Resolution rules: read both before trusting a gap
Kalshi
If the value of the S&P 500 Index is above $10,000 at any point after Issuance and before Dec 31, 2029, then the market resolves to Yes.
Polymarket
This market will immediately resolve to "Yes" if any Binance 1 minute candle for Bitcoin (BTC/USDT) between November 24, 2025, 14:00 and December 31, 2026, 23:59 in the ET timezone has a final "Low" price equal to or lower than the price specified in the title. Otherwise, this market will resolve to "No." The resolution source for this market is Binance, specifically the BTC/USDT "Low" prices available at https://www.binance.com/en/trade/BTC_USDT, with the chart settings on "1m" for one-minute candles selected on the top bar. Please note that the outcome of this market depends solely on the price data from the Binance BTC/USDT trading pair. Prices from other exchanges, different trading pairs, or spot markets will not be considered for the resolution of this market.
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Informational only — not financial advice. Odds are mirrored from each platform and may lag the live order book.