COST Options History — October 2025

In October 2025, COST traded between $908.75 and $954.20. ATM implied volatility averaged 20.5%, placing in the 13.3% IV rank vs the trailing year. The 30-day expected move averaged 6.0%. IV traded above realized volatility by 1.4% (HV 20d: 19.1%). Max pain ranged from $925.00 to $940.00. Net GEX was positive for 9 of 23 trading days. Term structure was in contango for 15 of 23 days. Put/call ratio averaged 0.70.

Notable Days

2025-10-09: Highest Volume — 87,925 contracts
2025-10-16: Largest IV spike — 20.1% change
2025-10-16: Highest IV Rank — 26.9%
2025-10-16: Largest Expected Move — 7.0%

Monthly Statistics

Metric	Avg	Min	Max	Open	Close
Price	$927.90	$908.75	$954.20	$916.65	$915.84
Max Pain	$930.22	$925.00	$940.00	$940.00	$925.00
ATM IV	20.5%	19.4%	24.2%	20.3%	21.1%
Expected Move	6.0%	5.5%	7.0%	5.8%	6.3%
HV 20d	19.1%	15.1%	21.4%	18.4%	19.5%
HV 60d	17.9%	16.6%	18.9%	16.8%	17.9%
IV Rank	13.3%	9.1%	26.9%	12.4%	15.7%
IV Percentile	31.7%	13.9%	57.5%	28.6%	44.0%
Term Structure	0.2%	-0.8%	1.0%	0.4%	-0.2%
VWIV	21.4%	19.8%	24.7%	20.9%	21.7%
Skew 25d	0.9%	-0.1%	1.9%	0.8%	0.6%
Skew 10d	2.1%	0.1%	7.2%	2.2%	1.4%
Call IV 25d	20.3%	19.4%	23.5%	20.1%	20.5%
Put IV 25d	21.2%	20.1%	24.7%	20.9%	21.1%
Bid-Ask Spread %	49.61	42.73	59.38	52.07	55.31
Gamma HHI	0.03	0.02	0.04	0.04	0.04
Net GEX	-14.7M	-202.4M	236.1M	-144.5M	-151.1M
Net DEX	-985.4M	-3.12B	428.7M	283.7M	-169.2M
Net VEX	-31.6M	-32.6M	-30.3M	-31.6M	-31.8M
Div Yield	0.0%	0.0%	0.0%	0.0%	0.0%
P/C Ratio	0.70	0.51	0.88	0.63	0.85
Total Volume	37,201.087	19,039	87,925	42,493	36,411
Total OI	306,647.783	269,868	336,554	322,037	309,442

Daily Data (23 trading days)

Date	Price	Max Pain	ATM IV	Exp Move	HV 20d	IV Rank	VWIV	Skew 25d	Term Str	GEX	DEX	VEX	P/C	Spread %	Call Vol	Put Vol	Call OI	Put OI
2025-10-01	$916.65	$940.00	20.3%	5.8%	18.4%	12.4%	20.9%	0.8%	0.4%	-144.5M	283.7M	-31.6M	0.63	52.07	26,013	16,480	171,485	150,552
2025-10-02	$917.05	$940.00	19.9%	5.5%	18.2%	11.0%	19.8%	1.0%	0.3%	-138.2M	113.7M	-32.1M	0.80	48.12	18,587	14,898	177,576	153,849
2025-10-03	$915.44	$940.00	19.6%	5.5%	17.6%	9.9%	19.8%	0.8%	0.2%	-119.9M	63.1M	-31.6M	0.74	57.34	27,639	20,459	181,169	154,477
2025-10-06	$908.75	$925.00	20.0%	5.9%	17.4%	11.4%	21.0%	0.8%	0.7%	-133.1M	404.6M	-30.9M	0.78	46.48	24,657	19,154	158,480	139,610
2025-10-07	$912.55	$930.00	20.0%	5.9%	16.9%	11.5%	20.9%	0.9%	0.4%	-97.6M	4.7M	-32.3M	0.51	42.73	22,475	11,460	167,400	146,410
2025-10-08	$913.41	$925.00	19.8%	5.8%	15.1%	10.8%	20.7%	0.7%	0.2%	-73.6M	-114.9M	-32.1M	0.71	44.98	14,210	10,037	170,858	148,831
2025-10-09	$940.91	$925.00	19.5%	5.8%	18.6%	9.7%	20.8%	1.2%	0.5%	236.1M	-2.87B	-32.2M	0.57	49.13	56,114	31,811	175,385	150,840
2025-10-10	$935.13	$930.00	20.7%	6.2%	18.5%	14.1%	22.1%	-0.1%	1.0%	129.6M	-1.94B	-32.3M	0.70	50.18	28,273	19,665	178,545	152,817
2025-10-13	$934.60	$930.00	21.4%	6.0%	18.3%	16.5%	21.6%	1.9%	-0.1%	28.8M	-1.42B	-31.9M	0.75	47.06	13,793	10,285	160,989	142,237
2025-10-14	$944.17	$930.00	20.4%	5.9%	18.5%	13.0%	22.0%	1.2%	0.6%	122.9M	-2.30B	-31.7M	0.88	49.15	19,145	16,790	165,442	145,528
2025-10-15	$954.20	$930.00	20.2%	6.0%	18.5%	12.0%	21.5%	0.1%	0.9%	224.5M	-3.12B	-32.0M	0.61	43.05	28,001	17,100	168,321	150,542
2025-10-16	$925.07	$930.00	24.2%	7.0%	21.1%	26.9%	24.7%	1.2%	-0.0%	-96.0M	-398.8M	-32.1M	0.88	50.29	31,510	27,809	169,779	152,604
2025-10-17	$933.99	$930.00	21.7%	6.3%	21.4%	17.5%	22.8%	1.0%	0.2%	-56.8M	-1.23B	-32.6M	0.63	47.02	28,627	18,139	176,137	160,417
2025-10-20	$933.56	$930.00	20.8%	6.0%	21.0%	14.2%	21.7%	0.8%	-0.8%	16.0M	-1.24B	-31.3M	0.63	53.14	14,738	9,340	138,370	131,498
2025-10-21	$937.66	$930.00	20.6%	5.9%	21.1%	13.7%	21.3%	1.1%	-0.3%	66.2M	-1.64B	-31.7M	0.67	42.76	11,394	7,645	144,805	134,855
2025-10-22	$943.81	$930.00	20.9%	6.0%	21.2%	14.8%	21.4%	0.8%	-0.5%	127.5M	-2.27B	-31.1M	0.56	48.87	17,442	9,693	148,341	136,961
2025-10-23	$942.31	$930.00	20.4%	5.9%	21.2%	12.9%	21.1%	1.4%	0.0%	127.1M	-2.06B	-31.1M	0.69	46.59	11,396	7,817	150,266	138,020
2025-10-24	$931.70	$930.00	19.4%	5.6%	19.6%	9.1%	20.6%	1.1%	0.0%	-27.9M	-1.10B	-30.3M	0.85	54.23	20,962	17,806	152,786	140,839
2025-10-27	$927.11	$930.00	19.8%	5.8%	19.6%	10.5%	20.9%	1.3%	1.0%	-47.3M	-772.4M	-30.5M	0.71	48.24	16,945	12,010	139,762	131,927
2025-10-28	$923.85	$930.00	20.4%	6.0%	18.8%	12.8%	21.3%	0.3%	-0.4%	-63.2M	-583.3M	-30.8M	0.76	51.42	14,511	11,100	146,918	137,419
2025-10-29	$911.54	$930.00	20.5%	6.3%	18.8%	13.2%	22.1%	1.0%	0.4%	-202.4M	428.7M	-30.7M	0.65	59.38	21,639	14,125	152,583	141,916
2025-10-30	$922.31	$925.00	20.5%	6.1%	19.3%	13.4%	21.3%	1.0%	-0.0%	-66.1M	-709.4M	-32.1M	0.53	53.46	17,961	9,559	159,911	146,000
2025-10-31	$915.84	$925.00	21.1%	6.3%	19.5%	15.7%	21.7%	0.6%	-0.2%	-151.1M	-169.2M	-31.8M	0.85	55.31	19,712	16,699	162,088	147,354