Polymarket$2.32BOIOpen interest: sum of pool liquidity across all active markets, reported by the Polymarket API.
Kalshi$350.67MOIOpen interest: total contracts outstanding across all active markets, reported by the Kalshi API.
Limitless$18.48MOIOpen interest: estimated from total volume traded (USDC). Limitless does not report a separate OI metric.Compare 2026 CA-11 Democratic Primary prediction market odds side by side across Polymarket, Kalshi. Platforms currently disagree by an average of 8.7pp, with the largest spread reaching 38.4pp. These price differences can signal arbitrage opportunities or reflect different trader sentiment. With $3.4K in combined trading volume across 11 outcomes, this is one of the notable cross-platform prediction markets.
Saikat ChakrabartiPolymarketKalshiCost: 62¢ per pair → pays $1 at resolution. Gross spread 38.4pp before fees.
View all arbs| Outcome | Polymarket | Kalshi | Spread |
|---|---|---|---|
Scott Wiener | 59%-1.0 | 93%±0 | 34.5pp spread |
Saikat Chakrabarti | 33% |
71%-1.0 |
| 38.4pp spread |
Connie Chan | 14%-0.5 | 36%-6.0 | 22.2pp spread |
M Matt Haney | - | 8%±0 | - |
C Christine Pelosi | - | 4%±0 | - |
L London Breed | - | 4%±0 | - |
N Nancy Pelosi | - | 3%±0 | - |
Jingchao Xiong | 1%— | - | - |
Darren Helton | 0%±0 | - | - |
Cole Bettles | 0%— | - | - |
David Ganezer | 0%— | 0%— | 0.3pp spread |
