Polymarket$3.29BOIOpen interest: sum of pool liquidity across all active markets, reported by the Polymarket API.
Kalshi$404.59MOIOpen interest: total contracts outstanding across all active markets, reported by the Kalshi API.
Limitless$27.64MOIOpen interest: estimated from total volume traded (USDC). Limitless does not report a separate OI metric.
Updated Today
If Lewis Evangelidis wins the nomination for the Republican Party to contest the 2026 Class II Massachusetts Senate seat, then the market resolves to Yes.
As of March 18, 2026, the Kalshi odds for Will Charlie Baker be the Republican nominee for the Senate in Massachusetts? are: John Deaton: 86%, Charlie Baker: 16%. These probabilities are derived from real-money trading and update in real time.
Will Charlie Baker be the Republican nominee for the Senate in Massachusetts? is currently available on Kalshi. 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.
