BIIB gamma exposure by strike
From the closing options book · October 20, 2026 · updated after every close
BIIB closed at 243.10 on October 20, 2026 with dealers net long $1.3M of gamma. The call wall was 240 (−1.3%), the put wall 220 (−9.5%) and the apex, the single largest gamma strike, 240.
BIIB largest gamma strikes within 4% of the close
The heaviest strike on the October 20, 2026 book was 240, carrying +$1.2M of dealer gamma, −1.3% from the close.
BIIB closed with dealers short gamma on 0 of the last 60 sessions. In short gamma, dealer hedging buys rallies and sells drops, which tends to extend moves; in long gamma it leans against them.
Positive (green) strikes are where dealers are long gamma and hedge against the move; negative (pink) strikes are where they are short and hedge with it. These are closing levels: where hedging was concentrated last night, not targets.
These are the October 20, 2026 closing numbers. Members see BIIB's map move live all session.
Common questions
At the October 20, 2026 close, BIIB's net dealer gamma exposure was +$1.3M: long gamma.
240, −1.3% from the 243.10 close on October 20, 2026.
220, −9.5% from the close on October 20, 2026.
Compare: gamma exposure by strike on other tickers
Measured from the closing options book and rebuilt after every close. Nothing on this page is live. Levels are where dealer hedging is concentrated, not targets or forecasts. Not investment advice.