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 Michigan Democratic Senate Primary Winner prediction market odds side by side across Kalshi, Polymarket. Platforms show similar odds, with an average spread of just 1.4pp. Close agreement often signals strong market consensus. With $170 in combined trading volume across 9 outcomes, this is one of the notable cross-platform prediction markets.
Abdul El-SayedPolymarketKalshiCost: 95¢ per pair → pays $1 at resolution. Gross spread 5.5pp before fees.
View all arbs| Outcome | Kalshi | Polymarket | Spread |
|---|---|---|---|
Mallory McMorrow | 57%±0 | 58%+0.5 | 1.0pp spread |
Haley Stevens | 20%±0 |
| 2.5pp spread |
Abdul El-Sayed | 23%+1.0 | 18%-1.0 | 5.5pp spread |
Rashida Tlaib | 2%±0 | 1%-1.7 | 0.9pp spread |
Andy Levin | 1%±0 | 1%±0 | 0.3pp spread |
Matt Sahr | 1%±0 | 1%±0 | 0.1pp spread |
Dana Nessel | 1%±0 | 0%±0 | 0.7pp spread |
Kristen McDonald Rivet | 1%±0 | 0%— | 0.8pp spread |
Sarah Anthony | 1%±0 | 0%— | 0.8pp spread |
