{"source":"polymarket","id":"526899","ticker":"spx-opens-up-or-down-on-may-27-2026","slug":"spx-opens-up-or-down-on-may-27-2026","title":"S&P 500 (SPX) Opens Up or Down on May 27?","description":"This market will resolve to \"Up\" if the official S&P 500 Index open price for S&P 500 (SPX) on May 27 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 27 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":"2026-05-26T12:11:17.804885Z","end_date":"2026-05-27T20:00:00Z","closed_time":null,"volume":8322.301936999998,"volume_24hr":8322.301937,"volume_24h_change":null,"normalized_vol_24hr":28.235050201416016,"normalized_volume":18.598695755004883,"liquidity":3114.6062,"open_interest":3288.1181,"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"},{"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":0.59,"top_outcome_prob_24h_change":0.08499999999999996,"top_outcome_volume_24h_change":8458.141741000001,"updated_at":"2026-05-27T05:18:32.700176Z","fetched_at":"2026-05-27T05:18:32.700176Z","added_at":"2026-05-26T12:12:00.568619Z","url":"https://polymarket.com/event/spx-opens-up-or-down-on-may-27-2026","chart_24h":[0.0,0.0,27.77777,48.32777,48.32777,130.375958,145.375958,145.375958,145.375958,175.375958,175.375958,175.375958,377.034181,560.182328,560.182328,560.182328,1190.405403,3155.235199,3413.811126,3667.144458,4563.526904,5361.068432,5561.068432,7001.794003000001,8322.301937],"markets":[{"source":"polymarket","id":"2360728","event_id":"526899","slug":"spx-opens-up-or-down-on-may-27-2026","question":"S&P 500 (SPX) Opens Up or Down on May 27?","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 27 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 27 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":[0.59,0.41],"probability":0.59,"spread":0.02,"active":true,"closed":false,"start_date":"2026-05-26T12:02:25.959744Z","end_date":"2026-05-27T20:00:00Z","closed_time":null,"volume":8458.141741,"volume_24hr":8458.141741000001,"prob_24h_change":0.08499999999999996,"volume_24h_change":8458.141741000001,"normalized_vol_24hr":30.244487762451172,"normalized_volume":23.99239158630371,"liquidity":3588.9009,"categories":["Finance"],"updated_at":"2026-05-27T05:19:19.872120Z","fetched_at":"2026-05-27T05:18:32.831230Z","added_at":"2026-05-26T12:12:00.650190Z","url":"https://polymarket.com/event/spx-opens-up-or-down-on-may-27-2026/spx-opens-up-or-down-on-may-27-2026","event_title":"S&P 500 (SPX) Opens Up or Down on May 27?","chart_24h":[0.505,0.655,0.615,0.66,0.63,0.675,0.675,0.67,0.59,0.565,0.575,0.655,0.53,0.525,0.49,0.495,0.585,0.615,0.65,0.605,0.615,0.59,0.555,0.59]}],"_meta":{"attribution":"pdata.world — aggregated prediction-market data across 8 platforms","canonical_url":"https://pdata.world/events/polymarket/526899","as_of":"2026-05-27T05:25:02.274479Z","docs":"https://api.pdata.world/docs","cite_as":"According to pdata.world (tracking Polymarket): \"S&P 500 (SPX) Opens Up or Down on May 27?\" — top market at 59% probability across 1 outcome","source_url":null}}