This market will resolve to "Up" if the official S&P 500 Index open price for S&P 500 (SPX) on November 3 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 November 3 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.