{"_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/1234935","as_of":"2026-10-23T13:48:53.407115Z","docs":"https://api.pdata.world/docs","cite_as":"According to pdata.world (tracking Polymarket): \"S&P 500 (SPX) Opens Up or Down on October 23?\" — 0% as of 2026-10-23 UTC. https://pdata.world/events/polymarket/1234935","source_url":"https://polymarket.com/event/spx-opens-up-or-down-on-october-23-2026"},"source":"polymarket","id":"1234935","ticker":"spx-opens-up-or-down-on-october-23-2026","slug":"spx-opens-up-or-down-on-october-23-2026","title":"S&P 500 (SPX) Opens Up or Down on October 23?","description":"This market will resolve to \"Up\" if the official S&P 500 Index open price for S&P 500 (SPX) on October 23 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 23 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":"2026-10-22T12:00:59Z","end_date":"2026-10-23T20:00:00Z","closed_time":null,"volume":5134.085375999999,"volume_24hr":5650.2483760000005,"volume_24h_change":null,"normalized_vol_24hr":28.432571411132812,"normalized_volume":16.578710556030273,"liquidity":283.52929,"open_interest":4663.615843,"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":0.004,"top_outcome_prob_24h_change":-0.491,"top_outcome_volume_24h_change":5695.248376,"updated_at":"2026-10-23T13:27:19.189833Z","fetched_at":"2026-10-23T13:27:19.189833Z","added_at":"2026-10-22T12:02:09.312987Z","url":"https://polymarket.com/event/spx-opens-up-or-down-on-october-23-2026","chart_24h":[0.0,0.0,0.0,0.0,0.0,0.0,20.0,359.62311200000005,384.795526,384.79552600000005,396.79552600000005,831.9438819999999,931.943882,981.943882,1041.943882,1093.762064,1189.280416,1827.8415280000002,1827.8415280000002,1865.9338360000002,2266.068593,2399.0622839999996,2535.142953,2541.095334,3609.0953759999998],"kind":"live","mutually_exclusive":false,"markets_total":1,"markets":[{"source":"polymarket","id":"6040674","event_id":"1234935","slug":"spx-opens-up-or-down-on-october-23-2026","question":"S&P 500 (SPX) Opens Up or Down on October 23?","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 23 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 23 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":[0.004,0.996],"probability":0.004,"spread":0.002,"active":true,"closed":false,"start_date":"2026-10-22T12:00:59Z","end_date":"2026-10-23T20:00:00Z","closed_time":null,"result":null,"volume":5650.248376,"volume_24hr":5695.248376,"prob_24h_change":-0.491,"volume_24h_change":5695.248376,"normalized_vol_24hr":29.56220054626465,"normalized_volume":21.89972496032715,"liquidity":1033.00967,"categories":["Finance"],"countries":[],"updated_at":"2026-10-23T13:27:19.407213Z","fetched_at":"2026-10-23T13:27:19.407213Z","added_at":"2026-10-22T12:02:09.394927Z","url":"https://polymarket.com/event/spx-opens-up-or-down-on-october-23-2026/spx-opens-up-or-down-on-october-23-2026","event_title":"S&P 500 (SPX) Opens Up or Down on October 23?","chart_24h":[0.495,0.64,0.645,0.585,0.57,0.505,0.55,0.46,0.36,0.55,0.575,0.53,0.49,0.51,0.53,0.565,0.52,0.64,0.52,0.395,0.375,0.39,0.115,0.01]}]}