{"source":"polymarket","id":"604630","ticker":"spx-opens-up-or-down-on-june-18-2026","slug":"spx-opens-up-or-down-on-june-18-2026","title":"S&P 500 (SPX) Opens Up or Down on June 18?","description":"This market will resolve to \"Up\" if the official S&P 500 Index open price for S&P 500 (SPX) on June 18 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 June 18 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":"2026-06-17T15:20:24.482098Z","end_date":"2026-06-18T20:00:00Z","closed_time":null,"volume":10914.398216,"volume_24hr":10914.398215999998,"volume_24h_change":null,"normalized_vol_24hr":25.184585571289062,"normalized_volume":18.3967342376709,"liquidity":4051.07246,"open_interest":5364.592661,"categories":["Finance"],"tags":[{"id":"102683","slug":"spx","label":"SPX"},{"id":"102169","slug":"hide-from-new","label":"Hide From New"},{"id":"102682","slug":"indicies","label":"Indicies"},{"id":"120","slug":"finance","label":"Finance"},{"id":"102127","slug":"up-or-down","label":"Up or Down"},{"id":"102281","slug":"daily","label":"Daily"}],"synthetic":false,"is_group":false,"group_key":null,"parent_event_id":null,"probability":null,"spread":null,"top_outcome":"","top_outcome_probability":0.965,"top_outcome_prob_24h_change":0.45999999999999996,"top_outcome_volume_24h_change":10914.398215999998,"updated_at":"2026-06-18T07:24:48.326992Z","fetched_at":"2026-06-18T07:24:48.326992Z","added_at":"2026-06-17T15:23:13.478917Z","url":"https://polymarket.com/event/spx-opens-up-or-down-on-june-18-2026","chart_24h":[0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,1.694914,1.694914,3.917135,168.348991,168.348991,187.335475,218.34547500000002,450.065475,830.165475,1444.276707,2932.902557,3402.1782699999994,4243.108454,4985.391786,5009.371786,6631.40926,8665.692116],"markets":[{"source":"polymarket","id":"2581107","event_id":"604630","slug":"spx-opens-up-or-down-on-june-18-2026","question":"S&P 500 (SPX) Opens Up or Down on June 18?","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 June 18 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 June 18 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":[0.965,0.035],"probability":0.965,"spread":0.01,"active":true,"closed":false,"start_date":"2026-06-17T15:17:42.998680Z","end_date":"2026-06-18T20:00:00Z","closed_time":null,"volume":10914.398216,"volume_24hr":10914.398215999998,"prob_24h_change":0.45999999999999996,"volume_24h_change":10914.398215999998,"normalized_vol_24hr":31.073665618896484,"normalized_volume":23.963539123535156,"liquidity":3791.6907,"categories":["Finance"],"countries":[],"updated_at":"2026-06-18T07:25:46.004555Z","fetched_at":"2026-06-18T07:24:48.422331Z","added_at":"2026-06-17T15:23:13.615904Z","url":"https://polymarket.com/event/spx-opens-up-or-down-on-june-18-2026/spx-opens-up-or-down-on-june-18-2026","event_title":"S&P 500 (SPX) Opens Up or Down on June 18?","chart_24h":[0.505,0.5,0.505,0.5,0.505,0.505,0.57,0.57,0.575,0.585,0.755,0.705,0.785,0.8,0.89,0.925,0.95,0.935,0.9,0.915,0.905,0.94,0.975]}],"_meta":{"attribution":"pdata.world — aggregated prediction-market data across 8 platforms","canonical_url":"https://pdata.world/events/polymarket/604630","as_of":"2026-06-18T07:29:24.626460Z","docs":"https://api.pdata.world/docs","cite_as":"According to pdata.world (tracking Polymarket): \"S&P 500 (SPX) Opens Up or Down on June 18?\" — top market at 96% probability across 1 outcome","source_url":null}}