GMAB Options Chain Analysis

Delayed CBOE data, snapshot 2026-08-18. Spot $32.84.

Put/Call (OI)

0.19

10k P / 55k C

Put/Call (Volume)

0.18

100 P / 571 C today

30d ATM IV

31%

annualized implied move

Call wall

$40

15k contracts

Put wall

$25

5k contracts

Tail hedging

0.5×

deep-OTM puts vs calls

What the positioning says

●Bullish positioning: only 0.19 puts per call outstanding.
●Call wall at $40 (15k contracts), 22% above spot — the upside strike the crowd is already parked on; often acts as near-term resistance.
●Put wall at $25 (5k contracts), 24% below spot — the hedge floor; often acts as support.
●Deep-OTM call OI is 2.1× deep-OTM put OI — speculative upside positioning dominates the tails.

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.

Open interest by expiry

Expiry	Call OI	Put OI	P/C	Volume today
2026-08-21	26k	3k	0.14	319
2026-09-18	2k	3k	1.34	106
2026-11-20	940	820	0.87	9
2026-12-18	19k	1k	0.06	37
2027-01-15	6k	1k	0.21	196
2027-02-19	215	226	1.05	4

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