{"_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/1176751","as_of":"2026-10-13T11:29:23.121738Z","docs":"https://api.pdata.world/docs","cite_as":"According to pdata.world (tracking Polymarket): \"S&P 500 (SPX) Opens Up or Down on October 13?\" — 28% as of 2026-10-13 UTC. https://pdata.world/events/polymarket/1176751","source_url":"https://polymarket.com/event/spx-opens-up-or-down-on-october-13-2026"},"source":"polymarket","id":"1176751","ticker":"spx-opens-up-or-down-on-october-13-2026","slug":"spx-opens-up-or-down-on-october-13-2026","title":"S&P 500 (SPX) Opens Up or Down on October 13?","description":"This market will resolve to \"Up\" if the official S&P 500 Index open price for S&P 500 (SPX) on October 13 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 13 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":"2026-10-12T12:00:58Z","end_date":"2026-10-13T20:00:00Z","closed_time":null,"volume":4536.609776,"volume_24hr":4536.609776,"volume_24h_change":null,"normalized_vol_24hr":27.265064239501953,"normalized_volume":16.106420516967773,"liquidity":776.6701,"open_interest":2580.27487,"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":0.285,"top_outcome_prob_24h_change":-0.34,"top_outcome_volume_24h_change":4536.609776,"updated_at":"2026-10-13T11:18:13.638282Z","fetched_at":"2026-10-13T11:18:13.638282Z","added_at":"2026-10-12T12:19:14.058704Z","url":"https://polymarket.com/event/spx-opens-up-or-down-on-october-13-2026","chart_24h":[0.0,0.0,0.0,0.0,0.0,0.0,100.0,343.44,443.44,686.88,766.88,1002.958432,1002.958432,1072.350473,1072.350473,1184.8137390000002,1275.343739,1476.886649,1602.886649,1602.886649,1890.9115290000002,2012.9083300000002,3110.432836,3446.752836,3450.4328360000004,3726.425694,4536.609776],"kind":"live","mutually_exclusive":false,"markets_total":1,"markets":[{"source":"polymarket","id":"5603342","event_id":"1176751","slug":"spx-opens-up-or-down-on-october-13-2026","question":"S&P 500 (SPX) Opens Up or Down on October 13?","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 13 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 13 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":[0.285,0.715],"probability":0.285,"spread":0.01,"active":true,"closed":false,"start_date":"2026-10-12T12:00:58Z","end_date":"2026-10-13T20:00:00Z","closed_time":null,"result":null,"volume":4536.609776,"volume_24hr":4536.609776,"prob_24h_change":-0.34,"volume_24h_change":4536.609776,"normalized_vol_24hr":28.944751739501953,"normalized_volume":20.80120277404785,"liquidity":858.8728,"categories":["Finance"],"countries":[],"updated_at":"2026-10-13T11:18:15.063724Z","fetched_at":"2026-10-13T11:18:15.063724Z","added_at":"2026-10-12T12:19:14.625218Z","url":"https://polymarket.com/event/spx-opens-up-or-down-on-october-13-2026/spx-opens-up-or-down-on-october-13-2026","event_title":"S&P 500 (SPX) Opens Up or Down on October 13?","chart_24h":[0.625,0.605,0.515,0.73,0.55,0.535,0.52,0.515,0.495,0.48,0.59,0.47,0.52,0.13,0.13,0.24,0.23,0.31,0.315,0.31,0.435,0.475,0.465,0.545,0.285]}]}