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 Z.ai have the best AI model at the end of December 2026?
Vol $5.7K today · $150.3K total
Kalshi is 8 points higher than Polymarket (8% vs 0%). They resolve on different dates (Dec 31 vs Dec 31), 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) | 0% | 8% |
| Change (24h) | -0.1 pt | +0.0 pt |
| Volume today | $5.7K | $0 |
| Total volume | $150.3K | $51 |
| Liquidity | $76.5K | — |
| Open interest | — | $51 |
| Resolves | 70d | 39mo |
| Tracked for | 35 hours | 13 days |
Resolution rules: read both before trusting a gap
Polymarket
This market will resolve according to the company which owns the model which has the highest arena rank based off the Chatbot Arena LLM Leaderboard (https://lmarena.ai/) when the table under the "Leaderboard" tab is checked on December 31, 2026, 12:00 PM ET. Results from the "Rank" section on the Leaderboard tab of https://lmarena.ai/leaderboard/text with the style control off will be used to resolve this market. Models will be ordered primarily by their leaderboard rank at the market’s check time. If two or more models are tied on rank, they will be ordered by their Arena score, including any underlying, unrounded, granular values reflected in the data below the leaderboard. If a tie remains, alphabetical order of company names as listed in this market group will be used as a final tiebreaker (e.g., if the two models are tied by exact arena score, “Google” would be ranked ahead of “xAI”). This market will resolve based on the company that occupies first place under this ranking system. The resolution source for this market is the Chatbot Arena LLM Leaderboard found at https://lmarena.ai/. If this resolution source is unavailable at check time, this market will remain open until the leaderboard comes back online and resolve based on the first check after it becomes available. If it becomes permanently unavailable, this market will resolve based on another resolution source.
Kalshi
If xAI has the highest-ranked AI model on the applicable index at 10:00 AM ET on Dec 31, 2029, 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.