ISRG Options Chain Analysis

Delayed CBOE data, snapshot 2026-08-19. Spot $391.4.

Put/Call (OI)

0.77

61k P / 79k C

Put/Call (Volume)

0.50

1k P / 3k C today

30d ATM IV

31%

annualized implied move

Call wall

$500

5k contracts

Put wall

$350

7k contracts

Tail hedging

0.6×

deep-OTM puts vs calls

What the positioning says

●Call wall at $500 (5k contracts), 28% above spot — the upside strike the crowd is already parked on; often acts as near-term resistance.
●Put wall at $350 (7k contracts), 11% 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	15k	9k	0.58	1k
2026-08-28	1k	1k	1.07	336
2026-09-04	563	540	0.96	62
2026-09-11	260	189	0.73	17
2026-09-18	12k	14k	1.16	658
2026-09-25	768	255	0.33	93
2026-10-02	71	132	1.86	64
2026-10-16	7k	6k	0.84	577
2026-11-20	2k	4k	1.72	112
2026-12-18	8k	5k	0.57	197
2027-01-15	11k	8k	0.74	200
2027-02-19	667	694	1.04	155
2027-03-19	1k	3k	1.99	25
2027-06-17	3k	3k	0.95	17
2028-01-21	10k	3k	0.32	52
2028-12-15	4k	2k	0.51	15

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