BIIB Options Chain Analysis

As of previous close (2026-10-02) · OPRA historical data

Spot $219.88 at that close. Nothing on this page comes from the session in progress.

Put/Call (OI)

0.77

17k P / 23k C

Put/Call (Volume)

0.58

686 P / 1k C that session

30d ATM IV

38%

annualized implied move

Call wall

$250

3k contracts

Put wall

$200

2k contracts

Tail hedging

2.1×

deep-OTM puts vs calls

What the positioning says

●Call wall at $250 (3k contracts), 14% above spot — the upside strike the crowd is already parked on; often acts as near-term resistance.
●Put wall at $200 (2k contracts), 9% below spot — the hedge floor; often acts as support.
●Deep-OTM put open interest is 2.1× deep-OTM call OI — an institutional hedging ladder sits under this stock.

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 2026-10-30. 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 that session
2026-10-09	166	77	0.46	1k
2026-10-16	3k	2k	0.63	98
2026-10-23	333	37	0.11	16
2026-10-30	80	39	0.49	10
2026-11-06	121	15	0.12	6
2026-11-13	0	0	—	1
2026-11-20	388	97	0.25	273
2026-12-18	5k	4k	0.90	9
2027-01-15	7k	7k	1.07	55
2027-03-19	1k	792	0.76	12
2027-04-16	124	176	1.42	0
2027-06-17	718	713	0.99	0
2027-09-17	161	34	0.21	0
2028-01-21	3k	1k	0.47	5
2029-01-19	42	5	0.12	9

Source: Cboe end-of-session option chains, summarized after each US market close and published from the following trading day — OPRA historical data. Under the OPRA plan options data becomes historical, and freely publishable, at the opening of the next trading session; data from the session in progress is never displayed or served here. Open interest is exchange-reported once a day. Research, not investment advice.