Security key
09062X103
- Security type / class
- Equity / COMMON STOCK
- Total 13F shares
- 131,083,249
- Total 13F value
- $18,365,221,765
- Share change
- +880,106
- Put/Call ratio
- 60%
- SEC-reported price per share
- $140.08
- Number of holders
- 894
- Value change
- +$165,798,563
- Number of buys
- 432
- Number of sells
- 341
- Shares outstanding
- 147,371,459
Holder snapshot
7 signals
Open additional details 1 more signal available
Security identity
Names, identifiers, and filing context for this profile.
1 source field
Report period
Q3 2025
Institutions
894
Top holders
10
BIIB full security history
Ownership snapshot
Full 13F holder table
BIOGEN INC. SEC filings
BIOGEN INC. company facts
BIOGEN INC. 13D/G history
Broader feeds
Ownership snapshot
Top reported holders of BIIB - BIOGEN INC. - COMMON STOCK (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
PRIMECAP MANAGEMENT CO/CA/
Disclosed value leader
VANGUARD GROUP INC
Comparable rows
15/15
Latest evidence
30 Sep 2025
13D/G
13F
3/4/5
Lead comparable stake: 10%
13D/G row: PRIMECAP MANAGEMENT CO/CA/
Showing 1-6 of 15 holder rows.
Quick read
PRIMECAP MANAGEMENT CO/CA/ leads the comparable SEC ownership view at 10%.
15 of 15 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens PRIMECAP MANAGEMENT CO/CA/'s linked filing trail.
Comparable ownership
Top 5
PRIMECAP MANAGEMENT CO/CA/
10%
BlackRock, Inc.
8.5%
STATE STREET CORP
5%
Caroline Dorsa
0.02%
VANGUARD GROUP INC
12%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-6 of 15 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| PRIMECAP MANAGEMENT CO/CA/ |
13D/G
13F
Company
|
10%
|
$2,094,853,956
14,954,697 shares
|
$0 | 30 Sep 2025 |
| BlackRock, Inc. |
13F
13D/G
Company
|
8.5%
from 13D/G
|
$1,702,431,056
13,555,466 shares
|
— | 30 Jun 2025 |
| STATE STREET CORP |
13D/G
13F
STATE STREET CORPORATION · Company
|
5%
|
$1,025,549,213
7,321,168 shares
|
$0 | 30 Sep 2025 |
| Caroline Dorsa |
3/4/5
Director
|
0.02%
|
$3,931,673
31,002 shares
|
— | 17 Jun 2025 |
| VANGUARD GROUP INC |
13F
Company
|
12%
|
$2,171,532,858
17,290,651 shares
|
— | 30 Jun 2025 |
| WELLINGTON MANAGEMENT GROUP LLP |
13F
Company
|
3.3%
|
$602,633,568
4,798,420 shares
|
— | 30 Jun 2025 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
13F holder rows
Institutional holders as of Q3 2025
Investor-level positions for this CUSIP, loaded as an interactive table.
Institutions
894
Shares
131,083,249
Rows available
894
| Investor | Option | Weight % | Change % | SEC-reported value | * Price | Shares | Share Change | Activity | Report Period |
|---|
* SEC-reported price is the security price as of the portfolio date and can indicate the last known price at which the security was still held. The marker flags a reported price that did not pass the local price check.
Compare Q3 2025 vs Q2 2025 Across Filers
Q2 2025 holders
856
Q3 2025 holders
894
Holder diff
38
| Investor | Q2 2025 Shares | Q3 2025 Shares | Share Diff | Share Chg % | Q2 2025 value | Q3 2025 value | Value change | Value Chg % |
|---|