Polymarket$3.30BOIOpen interest: sum of pool liquidity across all active markets, reported by the Polymarket API.
Kalshi$381.46MOIOpen 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 Carlos Alcaraz wins all 4 tennis Grand Slams in 2026, then the market resolves to Yes.
As of March 18, 2026, the Kalshi odds for How many Grand Slams will Carlos Alcaraz win in 2026? are: 2+ Grand Slam wins: 75%, 3+ Grand Slam wins: 47%, All 4 Grand Slam wins: 15%. These probabilities are derived from real-money trading and update in real time.
How many Grand Slams will Carlos Alcaraz win in 2026? 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.
