{"_meta":{"attribution":"Data aggregated by pdata.world (https://pdata.world) from 8 prediction-market venues; CC BY 4.0; source data © each venue.","canonical_url":"https://pdata.world/events/polymarket/1240335","as_of":"2026-10-26T17:04:46.117425Z","docs":"https://api.pdata.world/docs","cite_as":"According to pdata.world (tracking Polymarket): \"S&P 500 (SPX) Opens Up or Down on October 26?\" — 100% as of 2026-10-26 UTC. https://pdata.world/events/polymarket/1240335","source_url":"https://polymarket.com/event/spx-opens-up-or-down-on-october-26-2026"},"source":"polymarket","id":"1240335","ticker":"spx-opens-up-or-down-on-october-26-2026","slug":"spx-opens-up-or-down-on-october-26-2026","title":"S&P 500 (SPX) Opens Up or Down on October 26?","description":"This market will resolve to \"Up\" if the official S&P 500 Index open price for S&P 500 (SPX) on October 26 is higher than the official S&P 500 Index closing price for SPX on the most recent prior trading day.\n\nThis market will resolve to \"Down\" if the official S&P 500 Index open price for S&P 500 (SPX) on October 26 is lower than the official S&P 500 Index closing price for SPX on the most recent prior trading day.\n\nE.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.\n\nIf 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.\n\nIf SPX does not trade at all during the regular session, the market will resolve 50-50.\n\nIf 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.\n\nIf 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.\n\nThe resolution source for this market is the Wall Street Journal, specifically the Open/Close values published by the WSJ under \"Historical Prices\".\n\nUS: https://www.wsj.com/market-data/stocks\nEMEA: https://www.wsj.com/market-data/stocks/emea\nASIA: https://www.wsj.com/market-data/stocks/asia","image":"https://polymarket-upload.s3.us-east-2.amazonaws.com/s-and-p-500-1e40af6979.png","icon":"https://polymarket-upload.s3.us-east-2.amazonaws.com/s-and-p-500-1e40af6979.png","active":true,"closed":false,"start_date":"2026-10-23T12:00:59Z","end_date":"2026-10-26T20:00:00Z","closed_time":null,"volume":14840.894328999999,"volume_24hr":14820.894329,"volume_24h_change":null,"normalized_vol_24hr":29.30483627319336,"normalized_volume":20.95229148864746,"liquidity":29669.29799,"open_interest":12619.919338,"categories":["Finance"],"tags":[{"id":"102683","slug":"spx","label":"SPX"},{"id":"102127","slug":"up-or-down","label":"Up or Down"},{"id":"102281","slug":"daily","label":"Daily"},{"id":"102682","slug":"indicies","label":"Indicies"},{"id":"120","slug":"finance","label":"Finance"},{"id":"102169","slug":"hide-from-new","label":"Hide From New"}],"synthetic":false,"is_group":false,"group_key":null,"parent_event_id":null,"probability":null,"spread":null,"top_outcome":"","top_outcome_probability":0.9995,"top_outcome_prob_24h_change":0.4045000000000001,"top_outcome_volume_24h_change":14800.894329,"updated_at":"2026-10-26T16:38:28.439688Z","fetched_at":"2026-10-26T16:38:28.439688Z","added_at":"2026-10-23T12:19:13.170598Z","url":"https://polymarket.com/event/spx-opens-up-or-down-on-october-26-2026","chart_24h":[20.0,20.0,40.0,40.0,185.0,205.0,227.727273,227.727273,227.727273,227.727273,335.55548999999996,906.28549,1307.7109259999997,1346.929496,1362.348066,1362.348066,1367.3480659999998,1698.663207,1792.220266,1877.5036,1914.9872370000003,2201.110748,2366.5007480000004,5299.584529000001,14815.894328999999,14820.894329,14820.894329],"kind":"live","mutually_exclusive":false,"markets_total":1,"markets":[{"source":"polymarket","id":"6079845","event_id":"1240335","slug":"spx-opens-up-or-down-on-october-26-2026","question":"S&P 500 (SPX) Opens Up or Down on October 26?","group_item_title":null,"description":"This market will resolve to \"Up\" if the official S&P 500 Index open price for S&P 500 (SPX) on October 26 is higher than the official S&P 500 Index closing price for SPX on the most recent prior trading day.\n\nThis market will resolve to \"Down\" if the official S&P 500 Index open price for S&P 500 (SPX) on October 26 is lower than the official S&P 500 Index closing price for SPX on the most recent prior trading day.\n\nE.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.\n\nIf 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.\n\nIf SPX does not trade at all during the regular session, the market will resolve 50-50.\n\nIf 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.\n\nIf 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.\n\nThe resolution source for this market is the Wall Street Journal, specifically the Open/Close values published by the WSJ under \"Historical Prices\".\n\nUS: https://www.wsj.com/market-data/stocks\nEMEA: https://www.wsj.com/market-data/stocks/emea\nASIA: https://www.wsj.com/market-data/stocks/asia","image":"https://polymarket-upload.s3.us-east-2.amazonaws.com/s-and-p-500-1e40af6979.png","icon":"https://polymarket-upload.s3.us-east-2.amazonaws.com/s-and-p-500-1e40af6979.png","outcomes":["Up","Down"],"outcome_prices":[0.9995,0.0005],"probability":0.9995,"spread":0.001,"active":true,"closed":false,"start_date":"2026-10-23T12:00:59Z","end_date":"2026-10-26T20:00:00Z","closed_time":null,"result":null,"volume":14840.894328999999,"volume_24hr":14820.894329,"prob_24h_change":0.4045000000000001,"volume_24h_change":14800.894329,"normalized_vol_24hr":30.730440139770508,"normalized_volume":27.0683536529541,"liquidity":29669.29799,"categories":["Finance"],"countries":[],"updated_at":"2026-10-26T17:02:39.639460Z","fetched_at":"2026-10-26T17:02:39.639460Z","added_at":"2026-10-23T12:19:13.278150Z","url":"https://polymarket.com/event/spx-opens-up-or-down-on-october-26-2026/spx-opens-up-or-down-on-october-26-2026","event_title":"S&P 500 (SPX) Opens Up or Down on October 26?","chart_24h":[0.595,0.455,0.785,0.74,0.545,0.465,0.56,0.485,0.5,0.425,0.61,0.675,0.675,0.585,0.64,0.65,0.76,0.885,0.64,0.515,0.91,0.975,0.9995,0.9995,0.9995,0.9995]}]}