SPX Options History — September 2025

In September 2025, SPX traded between $6407.58 and $6696.05. ATM implied volatility averaged 12.6%, placing in the 9.2% IV rank vs the trailing year. The 30-day expected move averaged 3.7%. IV traded above realized volatility by 3.8% (HV 20d: 8.7%). Max pain ranged from $6050.00 to $6350.00. Net GEX was positive for 18 of 21 trading days. Term structure was in contango for 13 of 21 days. Put/call ratio averaged 1.22.

Notable Days

2025-09-25: Highest Volume — 4,713,165 contracts
2025-09-26: Largest IV drop — 10.0% change
2025-09-02: Highest IV Rank — 12.6%
2025-09-02: Largest Expected Move — 4.1%

Monthly Statistics

Metric	Avg	Min	Max	Open	Close
Price	$6580.72	$6407.58	$6696.05	$6407.58	$6678.45
Max Pain	$6195.00	$6050.00	$6350.00	$6050.00	$6350.00
ATM IV	12.6%	11.4%	13.8%	13.8%	12.9%
Expected Move	3.7%	3.4%	4.1%	4.1%	3.5%
HV 20d	8.7%	6.8%	9.8%	9.6%	6.8%
HV 60d	9.4%	8.7%	10.1%	10.1%	8.7%
IV Rank	9.2%	5.9%	12.6%	12.6%	10.2%
IV Percentile	27.9%	8.7%	46.8%	44.4%	33.3%
Term Structure	-0.0%	-0.3%	0.3%	0.2%	0.2%
VWIV	15.2%	13.4%	20.0%	15.5%	13.8%
Skew 25d	4.6%	3.8%	6.2%	6.2%	4.7%
Skew 10d	10.1%	8.6%	12.6%	12.6%	10.6%
Call IV 25d	10.7%	9.8%	11.7%	11.2%	10.9%
Put IV 25d	15.3%	13.7%	17.4%	17.4%	15.6%
Bid-Ask Spread %	5.49	3.71	8.37	8.37	7.60
Gamma HHI	0.02	0.02	0.03	0.02	0.02
Net GEX	51.72B	-24.11B	119.28B	-23.29B	46.35B
Net DEX	-2400.72B	-3052.91B	-1821.58B	-1821.58B	-2272.01B
Net VEX	-10.99B	-11.76B	-10.27B	-11.45B	-11.53B
Div Yield	0.0%	0.0%	0.0%	0.0%	0.0%
P/C Ratio	1.22	1.10	1.35	1.19	1.16
Total Volume	3,866,159.905	3,251,088	4,713,165	4,098,036	4,215,438
Total OI	20,965,785.333	18,847,486	23,174,016	20,541,497	20,297,015

Daily Data (21 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
2025-09-02	$6407.58	$6050.00	13.8%	4.1%	9.6%	12.6%	15.5%	6.2%	0.2%	-23.29B	-1821.58B	-11.45B	1.19	8.37	1,868,003	2,230,033	7,507,516	13,033,981
2025-09-03	$6434.73	$6050.00	13.3%	3.8%	9.6%	11.4%	14.2%	5.7%	-0.3%	30.85B	-2031.91B	-11.25B	1.16	7.92	1,704,633	1,975,949	7,616,808	13,162,717
2025-09-04	$6493.01	$6100.00	12.3%	3.6%	9.8%	8.4%	20.0%	5.1%	-0.3%	81.09B	-2396.15B	-10.88B	1.24	3.71	1,680,732	2,090,740	7,677,216	13,266,410
2025-09-05	$6477.38	$6115.00	11.9%	3.6%	9.8%	7.5%	15.2%	4.9%	0.1%	33.91B	-2284.67B	-11.05B	1.15	4.31	2,178,617	2,499,900	7,825,089	13,694,019
2025-09-08	$6493.65	$6125.00	12.0%	3.6%	9.4%	7.6%	16.0%	4.8%	0.1%	55.41B	-2381.65B	-10.74B	1.15	3.98	1,617,996	1,854,923	7,739,388	13,523,293
2025-09-09	$6509.26	$6150.00	11.8%	3.5%	9.4%	7.3%	15.1%	4.7%	0.1%	67.34B	-2449.78B	-10.63B	1.30	3.79	1,550,879	2,010,733	7,764,714	13,596,236
2025-09-10	$6527.52	$6150.00	12.0%	3.5%	8.9%	7.6%	16.1%	4.6%	-0.2%	79.21B	-2516.82B	-10.81B	1.26	3.88	1,750,776	2,200,103	7,794,227	13,860,379
2025-09-11	$6589.79	$6150.00	11.5%	3.4%	9.4%	6.3%	13.4%	4.0%	-0.2%	119.28B	-2902.25B	-10.39B	1.13	4.26	1,843,067	2,085,995	7,841,355	14,051,571
2025-09-12	$6588.30	$6160.00	11.4%	3.4%	9.4%	5.9%	14.7%	3.8%	0.1%	94.30B	-2876.92B	-10.41B	1.27	4.84	1,526,675	1,937,915	7,973,729	14,231,807
2025-09-15	$6610.56	$6175.00	12.2%	3.6%	9.3%	8.2%	14.3%	4.1%	0.1%	110.88B	-2963.47B	-10.27B	1.33	4.51	1,533,982	2,044,448	7,999,252	14,120,068
2025-09-16	$6610.67	$6200.00	12.8%	3.7%	9.3%	9.9%	15.0%	4.5%	0.2%	61.60B	-2921.85B	-10.64B	1.24	4.86	1,449,575	1,801,513	8,118,778	14,378,807
2025-09-17	$6598.30	$6200.00	12.7%	3.6%	8.9%	9.5%	15.2%	4.2%	-0.3%	41.71B	-2840.49B	-10.71B	1.34	6.80	1,467,554	1,965,946	8,125,521	14,544,863
2025-09-18	$6631.81	$6215.00	12.4%	3.6%	9.0%	8.9%	13.9%	4.0%	-0.3%	81.26B	-3052.91B	-10.76B	1.11	4.53	1,941,022	2,145,719	8,318,057	14,855,959
2025-09-19	$6662.76	$6250.00	12.3%	3.6%	8.6%	8.6%	15.4%	4.1%	0.1%	69.58B	-2190.61B	-10.76B	1.24	5.52	1,792,598	2,216,197	6,612,160	12,235,326
2025-09-22	$6696.05	$6250.00	12.6%	3.7%	7.2%	9.4%	14.0%	4.1%	0.1%	80.38B	-2326.20B	-10.67B	1.12	4.91	1,864,457	2,087,347	6,701,597	12,244,929
2025-09-23	$6656.88	$6250.00	13.6%	3.9%	7.6%	12.0%	17.0%	4.5%	0.1%	15.69B	-2083.53B	-11.39B	1.35	5.25	1,743,265	2,351,555	6,902,335	12,485,558
2025-09-24	$6630.60	$6255.00	13.5%	3.9%	7.8%	11.9%	15.3%	4.5%	-0.3%	-6.46B	-1979.80B	-11.55B	1.30	5.32	1,594,228	2,078,032	6,988,250	12,771,987
2025-09-25	$6598.14	$6275.00	13.7%	3.9%	8.0%	12.2%	16.3%	4.7%	-0.3%	-24.11B	-1830.92B	-11.76B	1.27	6.08	2,071,704	2,641,461	7,071,404	12,876,846
2025-09-26	$6640.75	$6300.00	12.3%	3.5%	8.2%	8.5%	13.8%	4.3%	0.1%	30.79B	-2094.80B	-11.59B	1.15	7.59	1,845,612	2,115,050	7,172,346	13,077,252
2025-09-29	$6658.96	$6325.00	12.8%	3.5%	7.7%	9.7%	14.2%	4.4%	0.3%	40.40B	-2196.73B	-11.48B	1.10	7.36	1,719,373	1,895,613	7,250,006	12,972,721
2025-09-30	$6678.45	$6350.00	12.9%	3.5%	6.8%	10.2%	13.8%	4.7%	0.2%	46.35B	-2272.01B	-11.53B	1.16	7.60	1,955,512	2,259,926	7,299,625	12,997,390