
Polymarket shows market prices. Foretrace adds AI probability estimates, opposing evidence and a price-dependent outcome or pass decision for each open market.
Sampled market observations, not AI forecasts. Lines connect available observations. Legend values are current provider quotes; chart points may be older.
These are market-implied probabilities, not AI forecasts. A displayed quote may differ from the price available for your order.
This market is closed. Its historical data remains available.
How research worksThis market will resolve to "Up" if the official S&P 500 Index open price for S&P 500 (SPX) on September 22 is higher than the official S&P 500 Index closing price for SPX on the most recent prior trading day. This market will resolve to "Down" if the official S&P 500 Index open price for S&P 500 (SPX) on September 22 is lower than the official S&P 500 Index closing price for SPX on the most recent prior trading day. E.g., ordinarily, a market on Monday would refer to the previous Friday for its most recent closing price, unless that Friday were a market holiday, in which case it would refer to Thursday, or the next most recent trading day. If the two prices are exactly equal, this market will resolve 50-50. Note that all figures will be rounded to the nearest cent using standard rounding. If SPX does not trade at all during the regular session, the market will resolve 50-50. If either of the relevant days are shortened (for example, due to a market holiday schedule), the official open/close price published by S&P 500 Index for that shortened session will still be used for resolution. If the previous trading day has no official closing price (for example, due to a trading halt into the market close, system issue, delisting, or other disruption), the market will use the last valid on-exchange trade price of the regular session as the effective closing price. The resolution source for this market is the Wall Street Journal, specifically the Open/Close values published by the WSJ under "Historical Prices". US: https://www.wsj.com/market-data/stocks EMEA: https://www.wsj.com/market-data/stocks/emea ASIA: https://www.wsj.com/market-data/stocks/asia
Retrieved 10/3/2026, 11:12:28 PM UTC. Provider data is cached for up to 60 seconds. The upstream quote timestamp can be older.