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 Illinois Republican Senate Primary Winner prediction market odds side by side across Polymarket, Kalshi. Platforms show similar odds, with an average spread of just 1.0pp. Close agreement often signals strong market consensus. With $65.5K in combined trading volume across 12 outcomes, this is one of the notable cross-platform prediction markets.
Don TracyPolymarketKalshiCost: 97¢ per pair → pays $1 at resolution. Gross spread 2.6pp before fees.
View all arbs| Outcome | Polymarket | Kalshi | Spread |
|---|---|---|---|
Don Tracy | 91%-0.5 | 94%-2.0 | 2.6pp spread |
Jeannie Evans | 6%+1.1 |
| 2.5pp spread |
Casey Chlebek | 0%— | 2%±0 | 1.8pp spread |
Doug Bennett | 0%— | 2%±0 | 1.8pp spread |
Jimmy Lee Tillman II | 0%±0 | 2%±0 | 1.9pp spread |
R. Cary Capparelli | 0%+1.0 | 1%±0 | 0.6pp spread |
John Goodman | 0%-1.3 | 1%±0 | 0.9pp spread |
Lloyd Jones | 0%— | - | - |
Panagioti Bartzis | 0%— | - | - |
Pamela Denise Long | 0%— | - | - |
CaSándra Claiborne | 0%— | - | - |
Januario Ortega | 0%— | - | - |
