The closing price for the S&P 500 (GSPC) in October 2018 was $2,711.74, on October 31, 2018. It was down 7.3% for the month. The latest price is $6,927.01.

DATE	OPEN	HIGH	LOW	CLOSE	VOLUME
October 31 2018	$2,705.60	$2,736.69	$2,705.60	$2,711.74	5,133,380,000
October 30 2018	$2,640.68	$2,685.43	$2,635.34	$2,682.63	5,125,600,000
October 29 2018	$2,682.65	$2,706.85	$2,603.54	$2,641.25	4,701,260,000
October 26 2018	$2,667.86	$2,692.38	$2,628.16	$2,658.69	4,804,330,000
October 25 2018	$2,674.88	$2,722.70	$2,667.84	$2,705.57	4,663,930,000
October 24 2018	$2,737.87	$2,742.59	$2,651.89	$2,656.10	4,738,670,000
October 23 2018	$2,721.03	$2,753.59	$2,691.43	$2,740.69	4,373,710,000
October 22 2018	$2,773.94	$2,778.94	$2,749.22	$2,755.88	3,331,270,000
October 19 2018	$2,775.66	$2,797.77	$2,760.27	$2,767.78	3,593,940,000
October 18 2018	$2,802.00	$2,806.04	$2,755.18	$2,768.78	3,639,300,000
October 17 2018	$2,811.67	$2,816.94	$2,781.81	$2,809.21	3,347,090,000
October 16 2018	$2,767.05	$2,813.46	$2,766.91	$2,809.92	3,460,260,000
October 15 2018	$2,763.83	$2,775.99	$2,749.03	$2,750.79	3,327,160,000
October 12 2018	$2,770.54	$2,775.77	$2,729.44	$2,767.13	4,024,010,000
October 11 2018	$2,776.87	$2,795.14	$2,710.51	$2,728.37	4,914,090,000
October 10 2018	$2,873.90	$2,874.02	$2,784.86	$2,785.68	4,554,260,000
October 09 2018	$2,882.51	$2,894.83	$2,874.27	$2,880.34	3,531,690,000
October 08 2018	$2,877.53	$2,889.45	$2,862.08	$2,884.43	3,381,820,000
October 05 2018	$2,902.54	$2,909.64	$2,869.29	$2,885.57	3,340,820,000
October 04 2018	$2,919.35	$2,919.78	$2,883.92	$2,901.61	3,510,370,000
October 03 2018	$2,931.69	$2,939.86	$2,921.36	$2,925.51	3,625,510,000
October 02 2018	$2,923.80	$2,931.42	$2,919.37	$2,923.43	3,432,620,000
October 01 2018	$2,926.29	$2,937.06	$2,917.91	$2,924.59	3,375,890,000

Daily pricing data for the S&P 500 dates back to 12/30/1927, and may be incomplete.