Quick answer
The Kairos terminal trades three venues in one aggregated order book: Kalshi, Polymarket, and Predict.fun. The Kairos API additionally serves market data for Hyperliquid's HIP-4 outcome markets. Aggregation means one global best bid and ask across every connected book.
Trading venues
| Venue | What it is | In the terminal |
|---|---|---|
| Kalshi | US CFTC-designated contract market, all 50 states, every category from politics to weather | Trading and data |
| Polymarket | The largest global prediction market, on Polygon, with a CFTC-regulated US exchange | Trading and data |
| Predict.fun | Blockchain-based prediction market on BNB Chain | Trading and data |
| Hyperliquid | HIP-4 outcome markets on the Hyperliquid L1 | Market data via the API |
Aggregation is the point of the list. The same event often trades on more than one venue at different prices, and a single-venue app cannot see the difference. Kairos builds one book across all of them, so the global best bid and best ask are visible and tradeable from one screen. Why that matters for pricing is covered in implied probability, and the venues themselves are ranked in the best prediction market guide.
Retired venues
Opinion, a decentralized venue, is sunset and no longer active. It remains in the API's provider list for historical data only.