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.
Next Astra Model (6.1+) released by December 31, 2026?
Vol $15.4K today · $106.3K total
Will the Federal Reserve hike rates by December 31, 2026?
Vol $4.9K today · $130.3K total
Polymarket is 1 points higher than Kalshi (84% vs 83%). Polymarket trades about 3.2× 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) | 84% | 83% |
| Change (24h) | -3.5 pt | +4.5 pt |
| Volume today | $15.4K | $4.9K |
| Total volume | $106.3K | $130.3K |
| Liquidity | $19.6K | — |
| Open interest | — | $72K |
| Resolves | 64d | 64d |
| Tracked for | 39 hours | 19 days |
Resolution rules: read both before trusting a gap
Polymarket
This market will resolve to "Yes" if OpenAI makes a GPT Astra model designated 6.1 or higher available to the general public between market creation and the specified date (ET). Otherwise, this market will resolve to "No". A qualifying model must be an OpenAI model designated as version 6.1 or higher that includes "Astra" in its name or model identifier, regardless of capitalization or surrounding prefixes, suffixes, dates, or descriptors. For example, GPT-6.1 Astra, Astra 6.1, or GPT Astra 7 would all qualify. GPT-6 Astra, including any rollout, promotion, Pro or Fast mode, or snapshot of it, will not qualify. Tier-labeled models such as GPT-5.6 Sol, GPT-5.6 Terra, or GPT-5.6 Luna and their successors, and task-specific or modality lines such as GPT-5.6-Cyber, Daybreak models, Codex, GPT Image, or Realtime models, will not qualify. A qualifying model must be launched and publicly accessible, including via open beta or open rolling waitlist signups. A closed beta or any form of private access will not suffice. The release must either be clearly defined and publicly announced by OpenAI as accessible to the general public, or otherwise be made publicly accessible and explicitly labeled on the company's official website. Labeling errors, placeholder text, or version names displayed on the website that do not correspond to a model that is actually accessible to the general publi…
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.