Polymarket$3.04BOIOpen interest: sum of pool liquidity across all active markets, reported by the Polymarket API.
Kalshi$356.20MOIOpen interest: total contracts outstanding across all active markets, reported by the Kalshi API.
Limitless$24.17MOIOpen 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 Midterms: House Popular Vote Margin of Victory are: Democrats 4-6%: 24%, Democrats 6-8%: 24%, Democrats 0-2%: 20%, Democrats 8-10%: 17%, Republicans 6%+: 15%. These probabilities are derived from real-money trading and update in real time.
2026 Midterms: House Popular Vote Margin of Victory 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.
