Resolves YES if the official S&P 500 close of October 21, 2026 is strictly higher than the official close of October 20, 2026 (S&P Dow Jones Indices, or Google Finance / Yahoo Finance ^GSPC). Resolves NO if it is equal or lower. Resolves N/A if US markets are closed on October 21. The market closes before the US market opens on October 21.