Polymarket$2.87BOIOpen interest: sum of pool liquidity across all active markets, reported by the Polymarket API.
Kalshi$354.88MOIOpen interest: total contracts outstanding across all active markets, reported by the Kalshi API.
Limitless$23.03MOIOpen interest: estimated from total volume traded (USDC). Limitless does not report a separate OI metric.Compare 2026 Marseille Mayoral Election prediction market odds side by side across Polymarket, Kalshi. Platforms show similar odds, with an average spread of just 1.4pp. Close agreement often signals strong market consensus. With $40.7K in combined trading volume across 5 outcomes, this is one of the notable cross-platform prediction markets.
Martine VassalPolymarketKalshiCost: 95¢ per pair → pays $1 at resolution. Gross spread 5.0pp before fees.
View all arbs| Outcome | Polymarket | Kalshi | Spread |
|---|---|---|---|
 Benoît Payan | 97%-2.5 | 97%+10.0 | 0.5pp spread |
 Franck Allisio | 3%+5.0 |
4%-9.0 |
| 0.6pp spread |
Martine Vassal | 0%±0 | 5%±0 | 5.0pp spread |
 Sébastien Delogu | 0%— | 1%±0 | 0.9pp spread |
 Erwann Davoux | 0%— | - | - |
