§ BIOTECHNOLOGY
USD · Biotechnology

BIIB

BIOGEN INC
USDSector · BiotechnologyMarket cap · $26.0BBeta · 0.17
LAST · MARKET CLOSE · SEP 18
218.36
−0.69 ▼ 0.32%PREV CLOSE · $219.05
§ 01 · PRICE
Price action
1D5D1M6MYTD1YMAX
OPEN 218.85HIGH 220.17LOW 217.0052W 110.03 — 202.41
EVENTSAUG 05 · ML SELL

§ 03 · SIGNAL STACK · WHAT THE INPUTS SAY

13F FLOW
525 increased/new, 294 decreased/exited (13F)
AC 13F Analysis
INSIDER
−$119K
1 txn · 90d

§ 04 · FUNDAMENTALS · THE BOOKS

P/E20.1P/B1.41
EPS (TTM)8.81
§ 05 · WHO OWNS IT
Top institutional holders
All holders →
FundShares% portΔ Q/Q
PRIMECAP MANAGEMENT CO/CA/14.8M2.1%±0%
VANGUARD CAPITAL MANAGEMENT LLC9.5M0.0%n/a
VANGUARD CAPITAL MANAGEMENT LLC9.5M0.0%n/a
Fidelity Management8.3M0.1%+36%
State Street7.2M0.0%+0%
VANGUARD PORTFOLIO MANAGEMENT LLC6.5M0.1%n/a
AC INTELLIGENCE

Top institutional owners for BIIB as of the most recent 13F reporting period (Q1 2026 · Period ended Mar 31). Δ Q/Q reflects share-count change vs. the prior filing — positive green means adding, negative red means trimming. Cross-reference with the ownership-mix bars below to see which strategy cohort is driving the flow.

§ 06 · WHO OWNS IT · BY STRATEGY

OTHER38.3% · 806 holders
QUALITY / COMPOUNDER24.7% · 36 holders
PASSIVE / INDEX18.6% · 14 holders
DEALER / BANK15.0% · 78 holders
INCOME / DEFENSIVE1.9% · 44 holders
DEEP VALUE1.2% · 2 holders
TACTICAL / MACRO1.1% · 5 holders
SYSTEMATIC / QUANT0.9% · 17 holders
GROWTH / MOMENTUM0.0% · 1 holder
ACTIVIST0.0% · 1 holder
AC INTELLIGENCE

Ownership mix by behavioral cohort. Top bars indicate which style of capital dominates the float — passive indexing, quality compounders, dealer/bank, systematic quant, etc. Big quality-compounder share means concentrated active conviction; heavy passive share means flows are dictated by index rebalances, not fundamentals.

§ 07 · INSIDER ACTIVITY · LAST 180 DAYS

DateInsiderActionShares$ value
AUG 05Minor LloydSELL593−$119K
AC INTELLIGENCE

0 insider buys, 1 sell in the last 180 days. Scheduled 10b5-1 sales are pre-programmed and neutral; discretionary clusters are the tape worth reading. Cross-reference with the signal stack above for context.

§ 08 · COVERAGE · OUR RECENT NOTES

No notes mention BIIB yet.