Polymarket$3.08BOIOpen interest: sum of pool liquidity across all active markets, reported by the Polymarket API.
Kalshi$380.07MOIOpen interest: total contracts outstanding across all active markets, reported by the Kalshi API.
Limitless$24.19MOIOpen interest: estimated from total volume traded (USDC). Limitless does not report a separate OI metric.
Updated Today
As of March 18, 2026, the Polymarket odds for 2026 Women’s US Open Winner (Tennis) are: Aryna Sabalenka: 40%, Elena Rybakina: 21%, Iga Swiatek: 13%, Coco Gauff: 6%, Jessica Pegula: 5%. These probabilities are derived from real-money trading and update in real time.
2026 Women’s US Open Winner (Tennis) is currently available on Polymarket. Check PredictMarketCap for cross-platform availability as new markets are added regularly.
Prediction market odds reflect the aggregate opinion of traders who risk real money on outcomes. The price of a share (e.g., 65¢) represents the market's implied probability (65%). Prices move as traders buy and sell based on new information, polls, and analysis.
