Biogen Inc. BIIB

Set alert

243.93 USD -10.53 (-4.14%)

At closeNov 5, 2026, 6:18 PM EST

240.88 -3.05 -1.25%

After hours · Nov 5, 6:18 PM ET

243.68 Day range 255.70

151.83 52-week range 258.78

Held by insiders 0.19%

Held by institutions 100.08%

Float held by institutions 100.27%

Institutions 1,516

Top institutional holders
Holder	% held	Shares	Value	Reported
FMR, LLC	12.32%	18,217,239	4.44B	Jun 29, 2026
Blackrock Inc.	10.81%	15,985,736	3.90B	Jun 29, 2026
Primecap Management Company	10.25%	15,154,606	3.70B	Jun 29, 2026
Vanguard Capital Management LLC	6.53%	9,651,117	2.35B	Jun 29, 2026
State Street Corporation	4.97%	7,344,327	1.79B	Jun 29, 2026
Vanguard Portfolio Management LLC	4.47%	6,604,936	1.61B	Jun 29, 2026

Top mutual fund holders
Holder	% held	Shares	Value	Reported
VANGUARD CHESTER FUNDS-Vanguard PRIMECAP Fund	5.66%	8,359,880	2.04B	Jun 29, 2026
Fidelity Contrafund	3.54%	5,227,192	1.28B	Sep 29, 2026
VANGUARD INDEX FUNDS-Vanguard Total Stock Market Index Fund	3.17%	4,687,985	1.14B	Jun 29, 2026
VANGUARD INDEX FUNDS-Vanguard 500 Index Fund	2.59%	3,827,862	933.73M	Jun 29, 2026
VANGUARD INDEX FUNDS-Vanguard Mid-Cap Index Fund	2.16%	3,199,078	780.35M	Jun 29, 2026
VANGUARD SPECIALIZED FUNDS-Vanguard Health Care Fund	1.86%	2,745,486	669.71M	Jul 30, 2026

BIIB insiders
Insider	Relation	Latest transaction	Date	Shares held
ALEXANDER SUSAN H	Officer	Conversion of Exercise of derivative security	Feb 5, 2026	61,889
DORSA CAROLINE D	Director	Stock Award(Grant)	Jun 16, 2025	31,002
GREGORY GINGER	Officer	Conversion of Exercise of derivative security	Feb 5, 2026	22,358
KRAMER ROBIN C.	Chief Financial Officer	Conversion of Exercise of derivative security	Feb 5, 2026	11,471
MANTAS JESUS B	Director	Stock Award(Grant)	Jun 8, 2026	11,263
MCDONNELL MICHAEL R	Chief Financial Officer	Conversion of Exercise of derivative security	Feb 9, 2025	24,341

Ownership