Ticker · CUSIP 09062X103

BIIB

BIOGEN INC

Healthcare·Drug Manufacturers - General

···Share

Holders (tracked)

Combined shares

15,549,779

Combined value

$2.74B

Last close

$177.35

Quarter

2025Q4

Price is +0.8% vs the avg quarter-end implied price across tracked holders.

Price · 1Y$177.35+58.74 (+49.52%)H $201.18 · L $116.49 · Avg Vol 1.6M

Congress buy

Tracked holders · last 8 quarters

+3 vs previous quarter over the last 8.

SEC event timeline

27 events

Wellington Management trimmed2026-02-17
−695,235 shares · 2025Q4
Position
Ken Griffin (Citadel Advisors) trimmed2026-02-17
−332,304 shares · 2025Q4
Position
Two Sigma Investments added2026-02-17
+46,530 shares · 2025Q4
Position
Izzy Englander (Millennium Mgmt) added2026-02-17
+14,396 shares · 2025Q4
Position
AQR Capital Management trimmed2026-02-17
−254,965 shares · 2025Q4
Position
Steve Cohen (Point72) trimmed2026-02-17
−1,059,709 shares · 2025Q4
Position
T. Rowe Price trimmed2026-02-17
−173,386 shares · 2025Q4
Position
Paul Tudor Jones (Tudor Investment) opened position2026-02-17
+33,300 shares · 2025Q4
Position
Larry Robbins (Glenview Capital) opened position2026-02-17
+290,605 shares · 2025Q4
Position
D.E. Shaw & Co. trimmed2026-02-17
−424,170 shares · 2025Q4
Position
Ray Dalio (Bridgewater Associates) exited2026-02-13
−39,983 shares · 2025Q4
Position
Renaissance Technologies trimmed2026-02-12
−565,210 shares · 2025Q4
Position
Norges Bank (Norway SWF) opened position2026-02-10
+2,638,834 shares · 2025Q4
Position
Ken Fisher (Fisher Asset Mgmt) added2026-02-09
+15,984 shares · 2025Q4
Position
Paul Tudor Jones (Tudor Investment) exited2025-12-09
−6,000 shares · 2025Q3
Position
Steve Cohen (Point72) added2025-11-14
+41,174 shares · 2025Q3
Position
Two Sigma Investments trimmed2025-11-14
−302,306 shares · 2025Q3
Position
D.E. Shaw & Co. trimmed2025-11-14
−888,283 shares · 2025Q3
Position
Izzy Englander (Millennium Mgmt) added2025-11-14
+435,688 shares · 2025Q3
Position
T. Rowe Price added2025-11-14
+131,530 shares · 2025Q3
Position
Wellington Management trimmed2025-11-14
−551,916 shares · 2025Q3
Position
AQR Capital Management added2025-11-14
+418,776 shares · 2025Q3
Position
Renaissance Technologies trimmed2025-11-13
−80,700 shares · 2025Q3
Position
Norges Bank (Norway SWF) exited2025-11-13
−2,264,177 shares · 2025Q3
Position
Ray Dalio (Bridgewater Associates) opened position2025-11-13
+39,983 shares · 2025Q3
Position
Ken Fisher (Fisher Asset Mgmt) trimmed2025-11-12
−11,852 shares · 2025Q3
Position
Norges Bank (Norway SWF) added2025-11-12
+185,647 shares · 2024Q3
Position

Insider activity

No insider transactions in the last 30 days.

View full insider history for BIIB →

Follow-the-investor returns

If you'd copied each holder of BIIB…

Cost basis inferred from each manager's quarter-over-quarter position changes. Sorted by % return on the position they're still holding.

Investor	First in	Cost basis	Return	Position value today
Paul Tudor Jones (Tudor Investment)	2016Q1	$127.48	+39.1%	$1.8M
Paul Tudor Jones (Tudor Investment)	2016Q1	$127.48	+39.1%	$1.8M
Steve Cohen (Point72)	2016Q1	$139.31	+27.3%	$177.6M
Steve Cohen (Point72)	2016Q1	$139.31	+27.3%	$177.6M
AQR Capital Management	2016Q1	$143.73	+23.4%	$271.1M
D.E. Shaw & Co.	2016Q1	$171.71	+3.3%	$2.3M
D.E. Shaw & Co.	2016Q1	$171.71	+3.3%	$2.3M
D.E. Shaw & Co.	2016Q1	$171.71	+3.3%	$2.3M
Ken Fisher (Fisher Asset Mgmt)	2016Q1	$171.97	+3.1%	$52.0M
Ken Griffin (Citadel Advisors)	2016Q1	$172.14	+3.0%	$72.2M
Ken Griffin (Citadel Advisors)	2016Q1	$172.14	+3.0%	$72.2M
Ken Griffin (Citadel Advisors)	2016Q1	$172.14	+3.0%	$72.2M
Izzy Englander (Millennium Mgmt)	2016Q1	$172.67	+2.7%	$8.3M
Izzy Englander (Millennium Mgmt)	2016Q1	$172.67	+2.7%	$8.3M
Izzy Englander (Millennium Mgmt)	2016Q1	$172.67	+2.7%	$8.3M
Larry Robbins (Glenview Capital)	2025Q4	$175.99	+0.8%	$51.5M
Two Sigma Investments	2016Q1	$186.94	-5.1%	$44.7M
Renaissance Technologies	2016Q1	$191.35	-7.3%	$70.8M
Norges Bank (Norway SWF)	2016Q1	$239.87	-26.1%	$468.0M
T. Rowe Price	2016Q1	$245.53	-27.8%	$140.5M
Wellington Management	2016Q1	$263.95	-32.8%	$629.8M

Who moved on this name in 2025Q4

Position changes reported for the latest quarter, grouped by direction.

New positions3

Norges Bank (Norway SWF)
+2,638,834
$464.4M
Larry Robbins (Glenview Capital)
+290,605
$51.1M
Paul Tudor Jones (Tudor Investment)
+33,300
$5.9M

Added to3

Two Sigma Investments
+46,530
$8.2M
Ken Fisher (Fisher Asset Mgmt)
+15,984
$2.8M
Izzy Englander (Millennium Mgmt)
+14,396
$2.5M

Trimmed7

Steve Cohen (Point72)
−1,059,709
$186.5M
Wellington Management
−695,235
$122.4M
Renaissance Technologies
−565,210
$99.5M
D.E. Shaw & Co.
−424,170
$74.6M
Ken Griffin (Citadel Advisors)
−332,304
$58.5M
AQR Capital Management
−254,965
$44.9M
T. Rowe Price
−173,386
$31K

Exited1

Ray Dalio (Bridgewater Associates)
−39,983
$5.6M

Institutional ownership over time

Distinct super-investors holding this ticker · combined dollar value, by quarter.

Quarter	Holders	Shares	Combined value	Δ holders
2022Q1	21	29,389,195	$294.64B	—
2022Q2	20	29,914,031	$246.46B	-1
2022Q3	21	31,185,985	$8.32B	+1
2022Q4	21	29,922,066	$8.29B	—
2023Q1	18	28,950,345	$8.05B	-3
2023Q2	19	26,227,136	$7.47B	+1
2023Q3	18	19,543,237	$5.02B	-1
2023Q4	17	18,795,006	$4.86B	-1
2024Q1	17	24,416,939	$5.27B	—
2024Q2	20	25,630,215	$5.94B	+3
2024Q3	20	12,721,344	$2.47B	—
2024Q4	19	9,999,312	$1.53B	-1
2025Q1	19	13,851,278	$1.90B	—
2025Q2	21	18,803,837	$2.36B	+2
2025Q3	18	16,102,392	$2.25B	-3
2025Q4	21	15,549,779	$2.74B	+3

Congress members trading this stock

Date	Member	Type	Amount range	Filing
2026-01-30	Gilbert Cisneros	Buy	$1K – $15K	PDF ↗
2025-05-15	Rob Bresnahan	Buy	$1K – $15K	PDF ↗
2025-04-08	Rob Bresnahan	Sell	$1K – $15K	PDF ↗
2025-02-25	Rob Bresnahan	Buy	$1K – $15K	PDF ↗

Who owns BIIB

21 super-investors · 2025Q4

Tracked stake

15.55M

Combined value

$2.74B

% of shares outstanding

—

shares-out unknown

Quarter action mix

New4Added5Trim12

#	Manager	Shares	Value	% of book	Last action	8Q trend
1	Wellington Management	3.55M	$625M	0.1%	Trim−695.2K
2	Steve Cohen Point72	2.81M	$495M	0.6%	Trim−1.06M
3	Norges Bank Norway SWF	2.64M	$464M	0.0%	New+2.64M
4	AQR Capital Management	1.53M	$269M	0.1%	Trim−255.0K
5	Izzy Englander Millennium Mgmt	1.13M	$198M	0.1%	Added+14.4K
6	Steve Cohen Point72	1.00M	$176M	0.2%	Trim−1.06M
7	T. Rowe Price	792.1K	$139M	0.0%	Trim−173.4K
8	Ken Griffin Citadel Advisors	407.0K	$72M	0.0%	Trim−332.3K
9	Renaissance Technologies	399.2K	$70M	0.1%	Trim−565.2K
10	Ken Fisher Fisher Asset Mgmt	293.3K	$52M	0.0%	Added+16.0K
11	Larry Robbins Glenview Capital	290.6K	$51M	1.0%	New+290.6K	—
12	Two Sigma Investments	251.8K	$44M	0.1%	Added+46.5K
13	Ken Griffin Citadel Advisors	162.0K	$29M	0.0%	Trim−332.3K
14	Izzy Englander Millennium Mgmt	101.1K	$18M	0.0%	Added+14.4K
15	D.E. Shaw & Co.	53.8K	$9M	0.0%	Trim−424.2K
16	Izzy Englander Millennium Mgmt	46.7K	$8M	0.0%	Added+14.4K
17	Ken Griffin Citadel Advisors	40.4K	$7M	0.0%	Trim−332.3K
18	Paul Tudor Jones Tudor Investment	23.0K	$4M	0.0%	New+33.3K
19	D.E. Shaw & Co.	13.2K	$2M	0.0%	Trim−424.2K
20	Paul Tudor Jones Tudor Investment	10.3K	$2M	0.0%	New+33.3K
21	D.E. Shaw & Co.	6.4K	$1M	0.0%	Trim−424.2K

Recent moves

20 transactions

TRIMD.E. Shaw & Co.
−424,170 · 2025Q4
TRIMSteve Cohen (Point72)
−1,059,709 · 2025Q4
TRIMWellington Management
−695,235 · 2025Q4
NEWPaul Tudor Jones (Tudor Investment)
+33,300 · 2025Q4
ADDTwo Sigma Investments
+46,530 · 2025Q4
TRIMT. Rowe Price
−173,386 · 2025Q4
TRIMAQR Capital Management
−254,965 · 2025Q4
ADDIzzy Englander (Millennium Mgmt)
+14,396 · 2025Q4
TRIMKen Griffin (Citadel Advisors)
−332,304 · 2025Q4
NEWLarry Robbins (Glenview Capital)
+290,605 · 2025Q4
SOLDRay Dalio (Bridgewater Associates)
−39,983 · 2025Q4
TRIMRenaissance Technologies
−565,210 · 2025Q4
NEWNorges Bank (Norway SWF)
+2,638,834 · 2025Q4
ADDKen Fisher (Fisher Asset Mgmt)
+15,984 · 2025Q4
SOLDPaul Tudor Jones (Tudor Investment)
−6,000 · 2025Q3
ADDIzzy Englander (Millennium Mgmt)
+435,688 · 2025Q3
TRIMD.E. Shaw & Co.
−888,283 · 2025Q3
ADDSteve Cohen (Point72)
+41,174 · 2025Q3
TRIMTwo Sigma Investments
−302,306 · 2025Q3
ADDT. Rowe Price
+131,530 · 2025Q3

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