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.
Updated Today
As of March 18, 2026, the Polymarket odds for Massachusetts Democratic Senate Primary Winner are: Ed Markey: 79%, Seth Moulton: 19%, Ayanna Pressley: 2%. These probabilities are derived from real-money trading and update in real time.
Massachusetts Democratic Senate Primary Winner 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.
