{"source":"polymarket","id":"713519","ticker":"spx-opens-up-or-down-on-july-20-2026","slug":"spx-opens-up-or-down-on-july-20-2026","title":"S&P 500 (SPX) Opens Up or Down on July 20?","description":"This market will resolve to \"Up\" if the official S&P 500 Index open price for S&P 500 (SPX) on July 20 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 July 20 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":false,"closed":true,"start_date":"2026-07-17T12:00:19Z","end_date":"2026-07-20T20:00:00Z","closed_time":"2026-07-20T22:28:40Z","volume":53621.500099000004,"volume_24hr":51941.808746999995,"volume_24h_change":null,"normalized_vol_24hr":49.721412658691406,"normalized_volume":24.08701515197754,"liquidity":null,"open_interest":27532.996263,"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":1.0,"top_outcome_prob_24h_change":0.135,"top_outcome_volume_24h_change":43150.687494,"updated_at":"2026-07-20T22:37:47.153926Z","fetched_at":"2026-07-20T22:37:47.153926Z","added_at":"2026-07-17T12:08:05.740859Z","url":"https://polymarket.com/event/spx-opens-up-or-down-on-july-20-2026","chart_24h":[8791.121252999998,9343.912218,10322.038141999998,11322.138037,14664.183031999999,23554.768896999998,26109.168897,30500.945167999995,50208.041599,50514.89826699999,50740.84826699999,51743.70826699999,51827.338266999985,51829.418266999994,51849.418266999994,51849.418266999994,52092.418266999994,52088.13255399999,52183.64255399999,52174.118747,51941.808746999995],"markets":[{"source":"polymarket","id":"2958619","event_id":"713519","slug":"spx-opens-up-or-down-on-july-20-2026","question":"S&P 500 (SPX) Opens Up or Down on July 20?","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 July 20 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 July 20 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":[1.0,0.0],"probability":1.0,"spread":0.001,"active":false,"closed":true,"start_date":"2026-07-17T12:00:19Z","end_date":"2026-07-20T20:00:00Z","closed_time":"2026-07-20T22:28:40Z","volume":53621.500099000004,"volume_24hr":51941.808746999995,"prob_24h_change":0.135,"volume_24h_change":43150.687494,"normalized_vol_24hr":49.72053909301758,"normalized_volume":32.9311637878418,"liquidity":0.0,"categories":["Finance"],"countries":[],"updated_at":"2026-07-21T08:00:52.412911Z","fetched_at":"2026-07-20T22:37:47.186401Z","added_at":"2026-07-17T12:08:05.874067Z","url":"https://polymarket.com/event/spx-opens-up-or-down-on-july-20-2026/spx-opens-up-or-down-on-july-20-2026","event_title":"S&P 500 (SPX) Opens Up or Down on July 20?","chart_24h":[0.865,0.855,0.94,0.945,0.9795,0.9875,0.9855,0.989,0.9995,0.9995,0.9995,0.9995,0.9995,0.9995,0.9995,0.9995,0.9995,0.9995,0.9995,1.0,1.0,1.0,1.0,1.0,1.0,1.0,1.0,1.0,1.0,1.0,1.0,1.0,1.0,1.0,1.0,1.0,1.0]}],"_meta":{"attribution":"pdata.world — aggregated prediction-market data across 8 platforms","canonical_url":"https://pdata.world/events/polymarket/713519","as_of":"2026-07-21T08:23:41.321130Z","docs":"https://api.pdata.world/docs","cite_as":"According to pdata.world (tracking Polymarket): \"S&P 500 (SPX) Opens Up or Down on July 20?\" — top market at 100% probability across 1 outcome","source_url":null}}