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 Roy Cooper be the Democratic Presidential nominee in 2028?
Vol $0 today · $3.6M total
Will Ruben Gallego win the 2028 Democratic presidential nomination?
Vol $22K today · $9M total
Both markets price this about the same, around 0%.
History starts when we first saw each market, so a newly added market has a short line.
| Kalshi | Polymarket | |
|---|---|---|
| Probability (Yes) | 1% | 0% |
| Change (24h) | +0.0 pt | +0.0 pt |
| Volume today | $0 | $22K |
| Total volume | $3.6M | $9M |
| Liquidity | — | $917.3K |
| Open interest | $3.1M | — |
| Resolves | 25mo | 25mo |
| Tracked for | 9 days | 9 days |
Resolution rules: read both before trusting a gap
Kalshi
If Roy Cooper wins and accepts the nomination for the Presidency for the Democratic party in 2028, then the market resolves to Yes.
Polymarket
This market will resolve to “Yes” if the named individual wins and accepts the 2028 nomination of the Democratic Party for U.S. president. Otherwise, this market will resolve to “No”. The resolution source for this market will be a consensus of official Democratic Party sources. Any replacement of the democratic nominee before election day will not change the resolution of the market.
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Informational only — not financial advice. Odds are mirrored from each platform and may lag the live order book.