When did BIIB join the S&P 500?

Biogen joined the S&P 500 index on 2003-11-13.

What sector is BIIB in?

BIIB is in the Health Care sector, Biotechnology industry.

BIIB — Biogen

Name: BIIB Institutional Holdings (13F) — 2026Q1
Creator: SEC EDGAR
License: https://www.sec.gov/data

Biotechnology · Health Care

Biogen is a biopharmaceutical company focused on the discovery, development, and delivery of therapies for neurological and neurodegenerative diseases. Its products include TECFIDERA, VUMERITY, AVONEX, PLEGRIDY, TYSABRI, and FAMPYRA for the treatment of multiple sclerosis; SPINRAZA for the treatment of spinal muscular atrophy (SMA); ADUHELM for the treatment of Alzheimer's disease; and FUMADERM for the treatment of severe plaque psoriasis.

Key Facts

Status	Active
Sector	Health Care
Industry	Biotechnology
Joined	2003-11-13
Tenure	22 yrs

S&P 500 Timeline

2003-11-13Joined S&P 500

Industry Peers

ABBV AMGN GILD INCY MRNA REGN VRTX

Sector Peers

A ABBV ABT ALGN AMGN BAX BDX BMY BSX CAH

Institutional Holdings (13F)

1,003 institutions hold BIIB, totaling 174.7M shares ($31.4B) · As of 2026Q1

Rank	Institution	Shares	Value
1	VANGUARD CAPITAL MANAGEMENT LLC	19.1M	$3.5B
2	BlackRock, Inc.	16.0M	$2.9B
3	PRIMECAP MANAGEMENT CO/CA/	14.8M	$2.7B
4	Employees Provident Fund Board	11.1M	$2.4B
5	FMR LLC	12.8M	$2.3B
6	BARCLAYS PLC	9.1M	$1.8B
7	STATE STREET CORP	7.2M	$1.3B
8	VANGUARD PORTFOLIO MANAGEMENT LLC	6.5M	$1.2B
9	MORGAN STANLEY	6.7M	$1.1B
10	GEODE CAPITAL MANAGEMENT, LLC	4.3M	$793M

View all holders →

Data source: Wikipedia · CC BY-SA 4.0 · SEC EDGAR 13F · Updated 2026-07-10