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BIIB Institutional Ownership & 13F Holders | SmartMoneyDB

BIIBBIOGEN INC

COM · CUSIP 09062X103

Smart Money Ownership

Of the 14 tracked institutions holding BIIB, 8 have a 3-year clone track record — 8 of them beat the S&P. Average holder's clone alpha: +5.8pt. It's a gauge of who owns the name, not just how many.

Steve Cohen

$148.4M · 0.3% of book

+11.9pt

Jim Simons

$37.3M · 0.1% of book

BIIB (BIOGEN INC) Institutional Ownership Summary

Among the 14 tracked institutional investors we monitor, BIIB (BIOGEN INC) is held with a combined value of $11.11B across 61,332,163 shares. The largest holder is VANGUARD GROUP INC with a position worth $3.07B (0.04% of their portfolio). 9 funds increased their holdings. 5 funds reduced their position.

Total Institutional Value

$11.11B

Total Shares Held

61,332,163

Institutional Holders

% of Shares Outstanding

41.5%

of 147.64M shares · SEC 2026-04-27

Days to Cover

4.1+10.3%

5.72M shares short · FINRA 2026-06-30

Tracked 13F institutions hold 41.5% of BIIB's shares outstanding. This is a floor: 13F filings arrive on a ~45-day lag and we track only a subset of institutional filers, so true institutional ownership is higher. Shares-outstanding is the latest SEC cover-page figure (as of 2026-04-27), not a live float.

This Quarter's Biggest Movers

Ranked by estimated dollars moved (share change × implied price). 13F data lags up to 45 days.

Biggest Buyers

FMR LLC+36% shares~$620.3M BlackRock, Inc.+8% shares~$214.4M AQR CAPITAL MANAGEMENT LLC+26% shares~$71.0M VANGUARD GROUP INC+1% shares~$27.4M CITADEL ADVISORS LLC+242% shares~$17.9M

13F Institutional Holders

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WELLINGTON MANAGEMENT GROUP LLP

0.10% of book-16.6%

$542.96M

AQR CAPITAL MANAGEMENT LLC

0.16% of book+25.8%

$346.24M

Point72 Asset Management, L.P.

0.26% of book-71.2%

$148.43M

PRICE T ROWE ASSOCIATES INC /MD/

0.01% of book-15.1%

$123.28M

ADAGE CAPITAL PARTNERS GP, L.L.C.

0.09% of book+13.3%

$61.13M

Fisher Asset Management, LLC

0.02% of book+6.6%

$57.31M

#	Fund	Value↓	Shares	Portfolio %	Change
1	VANGUARD GROUP INC	$3.07B	17,447,092	0.04%	+0.9%
2	BlackRock, Inc.	$2.93B	15,974,601	0.05%	+7.9%
3	FMR LLC	$2.35B	12,807,541	0.12%	+35.9%
4	STATE STREET CORP	$1.31B	7,167,922	0.05%	+0.1%
5	WELLINGTON MANAGEMENT GROUP LLP	$542.96M	2,961,641	0.10%	-16.6%
6	AQR CAPITAL MANAGEMENT LLC	$346.24M	1,923,557	0.16%	+25.8%
7	Point72 Asset Management, L.P.	$148.43M	809,617	0.26%	-71.2%
8	PRICE T ROWE ASSOCIATES INC /MD/	$123.28M	672,427	0.01%	-15.1%
9	ADAGE CAPITAL PARTNERS GP, L.L.C.	$61.13M	333,457	0.09%	+13.3%
10	Fisher Asset Management, LLC	$57.31M	312,618	0.02%	+6.6%

Congress Trading

7 members · 24 disclosed trades in BIIB

Member	Type	Amount	Date
Gilbert Cisneros	Buy	$1,001 - $15,000	Jun 5, 2026
Maria Elvira Salazar	Sell	$15,001 - $50,000	Jun 2, 2026
Maria Elvira Salazar	Buy	$1,001 - $15,000	May 12, 2026
Maria Elvira Salazar	Buy	$50,001 - $100,000

Frequently Asked Questions

Which institutional investors own the most BIIB stock?

As of the latest SEC 13F filings, VANGUARD GROUP INC is the largest institutional holder of BIIB with a position worth $3.07B, representing 0.04% of their portfolio. In total, 14 institutional investors hold BIIB with a combined value of $11.11B.

What percentage of BIIB is owned by institutional investors?

Institutional investors hold $11.11B worth of BIIB stock across 14 positions. The largest institutional holder is VANGUARD GROUP INC with $3.07B in holdings.

What is a 13F filing and why does it matter for BIIB?

A 13F filing is a quarterly report required by the SEC from institutional investment managers with over $100 million in assets. It discloses their holdings in U.S. equities. For BIIB, these filings reveal which major funds are accumulating or reducing positions, providing insights into institutional sentiment.

Track BIIB institutional moves

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