SPGI Options Chain Analysis

Delayed CBOE data, snapshot 2026-08-18. Spot $410.53.

Put/Call (OI)

1.43

11k P / 8k C

Put/Call (Volume)

1.31

984 P / 751 C today

30d ATM IV

28%

annualized implied move

Call wall

$420

927 contracts

Put wall

$400

1k contracts

Tail hedging

0.6×

deep-OTM puts vs calls

What the positioning says

●Defensive positioning: 1.43 puts outstanding per call — holders are hedging rather than selling.
●Call wall at $420 (927 contracts), 2% above spot — the upside strike the crowd is already parked on; often acts as near-term resistance.
●Put wall at $400 (1k contracts), 3% below spot — the hedge floor; often acts as support.

Open interest by strike

All expiries combined. Amber lines mark the call and put walls; the dashed line is spot.

IV term structure

At-the-money implied volatility per expiry.

Volatility smile

IV by strike — expiry 2026-09-18. A steep left side = expensive downside protection.

30-day implied volatility history

Daily ATM IV (~30 DTE bucket) collected since March 2026. Rising IV into an event = the market bracing; collapsing IV after = the crush.

Open interest by expiry

Expiry	Call OI	Put OI	P/C	Volume today
2026-08-21	2k	2k	1.05	309
2026-08-28	254	439	1.73	80
2026-09-04	130	603	4.64	51
2026-09-11	75	409	5.45	42
2026-09-18	1k	2k	1.80	362
2026-09-25	36	207	5.75	67
2026-10-02	21	35	1.67	51
2026-10-16	2k	2k	1.02	107
2026-11-20	688	663	0.96	30
2026-12-18	130	196	1.51	27
2027-01-15	728	2k	2.09	471
2027-02-19	61	52	0.85	7
2027-03-19	254	228	0.90	34
2027-06-17	156	535	3.43	41
2027-12-17	135	102	0.76	8
2028-01-21	223	186	0.83	48

Source: CBOE delayed quotes, refreshed daily after US market close. Open interest is exchange-reported and lags one session. Research, not investment advice.