{"source":"polymarket","id":"513297","ticker":"spx-opens-up-or-down-on-may-26-2026","slug":"spx-opens-up-or-down-on-may-26-2026","title":"S&P 500 (SPX) Opens Up or Down on May 26?","description":"This market will resolve to \"Up\" if the official S&P 500 Index open price for S&P 500 (SPX) on May 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 May 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":"2026-05-22T12:51:53.212321Z","end_date":"2026-05-26T20:00:00Z","closed_time":null,"volume":80842.47941499998,"volume_24hr":71309.634296,"volume_24h_change":null,"normalized_vol_24hr":43.98517608642578,"normalized_volume":29.173677444458008,"liquidity":179784.39168,"open_interest":50314.915825,"categories":["Finance"],"tags":[{"id":"102127","slug":"up-or-down","label":"Up or Down"},{"id":"102682","slug":"indicies","label":"Indicies"},{"id":"102169","slug":"hide-from-new","label":"Hide From New"},{"id":"102683","slug":"spx","label":"SPX"},{"id":"102281","slug":"daily","label":"Daily"},{"id":"120","slug":"finance","label":"Finance"},{"id":"104181","slug":"rewards-automation-400-4pt5-50-1","label":"Rewards Automation 400, 4.5, 50 (1)"}],"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":0.11450000000000005,"top_outcome_volume_24h_change":63805.35482600001,"updated_at":"2026-05-26T15:55:42.681219Z","fetched_at":"2026-05-26T15:55:42.681219Z","added_at":"2026-05-22T12:46:48.884402Z","url":"https://polymarket.com/event/spx-opens-up-or-down-on-may-26-2026","chart_24h":[7504.279469999998,7569.908356999997,7515.968356999999,7783.625827999998,7814.753477999999,8194.087078999999,8876.463843999998,11097.709534999996,11233.126184999996,13452.628299999997,13457.828299999997,14456.635342999996,15116.610423999997,17355.065423999997,18377.984911999996,21135.568243999995,22152.913587999996,24060.382838,24516.120399999996,24009.048112,22893.784564000005,23598.407896000004,23784.476215000002,25886.39458600001,30271.282348000004,32175.33126800001,31796.156043000014,36180.98278900001,36379.18999700001,47509.676578000006,47497.68705100001,53513.73161000001,61335.898053000004,61455.97805300001,71309.634296],"markets":[{"source":"polymarket","id":"2331430","event_id":"513297","slug":"spx-opens-up-or-down-on-may-26-2026","question":"S&P 500 (SPX) Opens Up or Down on May 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 May 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 May 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":"2026-05-22T12:33:00.637100Z","end_date":"2026-05-26T20:00:00Z","closed_time":null,"volume":80842.47941499998,"volume_24hr":71309.634296,"prob_24h_change":0.11450000000000005,"volume_24h_change":63805.35482600001,"normalized_vol_24hr":48.821533203125,"normalized_volume":37.46501159667969,"liquidity":179784.39168,"categories":["Finance"],"updated_at":"2026-05-26T15:41:59.705657Z","fetched_at":"2026-05-26T15:27:02.382712Z","added_at":"2026-05-22T12:46:48.942612Z","url":"https://polymarket.com/event/spx-opens-up-or-down-on-may-26-2026/spx-opens-up-or-down-on-may-26-2026","event_title":"S&P 500 (SPX) Opens Up or Down on May 26?","chart_24h":[0.885,0.885,0.91,0.91,0.92,0.93,0.945,0.935,0.96,0.95,0.95,0.895,0.88,0.92,0.875,0.895,0.94,0.94,0.935,0.93,0.945,0.955,0.9565,0.8975,0.915,0.932,0.942,0.981,0.9855,0.987,0.991,0.9995,0.9995,0.9995,0.9995]}],"_meta":{"attribution":"pdata.world — aggregated prediction-market data across 8 platforms","canonical_url":"https://pdata.world/events/polymarket/513297","as_of":"2026-05-26T16:06:12.933472Z","docs":"https://api.pdata.world/docs","cite_as":"According to pdata.world (tracking Polymarket): \"S&P 500 (SPX) Opens Up or Down on May 26?\" — top market at 100% probability across 1 outcome","source_url":null}}