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 the number of total seats for justices of the Supreme Court of the United States has been expanded or contracted after Issuance and before Jan 20, 2029, then the market resolves to Yes.
As of March 18, 2026, the Kalshi odds for Will the size of the Supreme Court be changed during Trump's Presidency? are: Before Jan 20, 2029: 7%. These probabilities are derived from real-money trading and update in real time.
Will the size of the Supreme Court be changed during Trump's Presidency? 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.
