BIOGEN INC. (BIIB)
Every FINRA and SEC series the site collects for BIOGEN INC.: short interest with days to cover, daily short sale volume, fails to deliver and Form 4 insider trades. Listed on Nasdaq, classified by the SEC as biological products, (no diagnostic substances).
5.2M
Short interest
settlement 2026-08-14
6.1
Days to cover
-4.8% vs prior
61.4%
Short share of volume
2026-09-11
135
Fails to deliver
settlement 2026-08-07
-$240K
Insider flow, 90 days
0 buys, 2 sells
As of 2026-09-11.
Short interest
FINRA, twice a month; the last 12 months shown, all 48 settlements in the JSONAs of 14 August 2026, short interest in BIIB is 5,190,555 shares, down 808,578 shares over the last month. Over the last 48 readings it ranged from 2,576,781 shares (13 December 2024) to 6,777,473 shares (28 November 2025). At the reported average volume of 847K shares a day that is 6.1 days to cover, elevated.
Embed this chartfree, with the attribution line it carries
<iframe src="https://xoomar.com/embed/stocks/biib" width="100%" height="440" style="border:0;max-width:100%" loading="lazy" title="XOOMAR chart"></iframe>
| Settlement | Shares short | Change | Avg daily volume | Days to cover |
|---|---|---|---|---|
| 2026-08-14 | 5,190,555 | -4.8% | 847,068 | 6.13 |
| 2026-07-31 | 5,453,901 | -9.1% | 1,153,245 | 4.73 |
| 2026-07-15 | 5,999,133 | +4.8% | 1,739,800 | 3.45 |
| 2026-06-30 | 5,723,194 | +10.3% | 1,382,477 | 4.14 |
| 2026-06-15 | 5,188,836 | +8.8% | 918,726 | 5.65 |
| 2026-05-29 | 4,771,495 | +0.9% | 1,063,313 | 4.49 |
| 2026-05-15 | 4,729,958 | +5.7% | 1,122,410 | 4.21 |
| 2026-04-30 | 4,475,470 | +1.4% | 1,247,291 | 3.59 |
| 2026-04-15 | 4,414,958 | +15.4% | 1,439,919 | 3.07 |
| 2026-03-31 | 3,826,441 | -11.7% | 1,104,246 | 3.47 |
| 2026-03-13 | 4,334,795 | +3.1% | 842,122 | 5.15 |
| 2026-02-27 | 4,202,912 | -7.5% | 908,274 | 4.63 |
| 2026-02-13 | 4,545,171 | -3.1% | 1,854,090 | 2.45 |
| 2026-01-30 | 4,692,637 | +0.3% | 1,296,294 | 3.62 |
| 2026-01-15 | 4,678,036 | +4.7% | 1,782,177 | 2.62 |
| 2025-12-31 | 4,466,337 | -32.2% | 2,674,703 | 1.67 |
| 2025-12-15 | 6,590,958 | -2.8% | 1,797,983 | 3.67 |
| 2025-11-28 | 6,777,473 | +10.4% | 2,080,199 | 3.26 |
| 2025-11-14 | 6,140,844 | +8.8% | 1,922,869 | 3.19 |
| 2025-10-31 | 5,644,654 | +8.7% | 1,566,934 | 3.60 |
| 2025-10-15 | 5,191,008 | +6.4% | 1,926,364 | 2.69 |
| 2025-09-30 | 4,880,043 | -4.8% | 1,636,581 | 2.98 |
| 2025-09-15 | 5,125,778 | +8.6% | 1,704,531 | 3.01 |
| 2025-08-29 | 4,720,975 | +13.6% | 1,316,930 | 3.58 |
Daily short volume
FINRA Reg SHO, last 60 sessions. JSONAs of 11 September 2026, the short share of BIIB volume is 61.4%, down 12.3 points over the last five sessions. Over the last 52 readings it ranged from 34.5% (8 July 2026) to 81.4% (26 August 2026). The latest reading is 3.4 points above the 30-session average of 58.0%, on 470K shares reported.
| Date | Short volume | Total volume | Short share | Exempt |
|---|---|---|---|---|
| 2026-09-11 | 289K | 470K | 61.4% | 0 |
| 2026-09-10 | 264K | 406K | 65.0% | 0 |
| 2026-09-09 | 141K | 262K | 54.0% | 360 |
| 2026-09-08 | 169K | 240K | 70.4% | 305 |
| 2026-09-04 | 136K | 204K | 66.7% | 0 |
| 2026-09-03 | 140K | 190K | 73.8% | 92 |
| 2026-09-02 | 297K | 482K | 61.6% | 20 |
| 2026-09-01 | 165K | 271K | 60.9% | 248 |
| 2026-08-31 | 134K | 221K | 60.4% | 12 |
| 2026-08-28 | 120K | 171K | 70.5% | 1 |
| 2026-08-27 | 137K | 183K | 75.1% | 40 |
| 2026-08-26 | 207K | 255K | 81.4% | 0 |
| 2026-08-25 | 128K | 215K | 59.4% | 96 |
| 2026-08-24 | 119K | 220K | 53.9% | 27 |
| 2026-08-21 | 128K | 263K | 48.9% | 600 |
| 2026-08-20 | 151K | 308K | 49.0% | 1 |
| 2026-08-19 | 143K | 279K | 51.3% | 0 |
| 2026-08-18 | 171K | 287K | 59.5% | 0 |
| 2026-08-17 | 130K | 225K | 57.9% | 406 |
| 2026-08-14 | 112K | 188K | 59.4% | 0 |
| 2026-08-13 | 177K | 328K | 54.0% | 1 |
| 2026-08-12 | 179K | 294K | 60.9% | 101 |
| 2026-08-11 | 183K | 363K | 50.5% | 310 |
| 2026-08-10 | 143K | 273K | 52.3% | 278 |
| 2026-08-07 | 162K | 291K | 55.6% | 21,142 |
| 2026-08-06 | 135K | 344K | 39.1% | 138 |
| 2026-08-05 | 182K | 330K | 55.0% | 49 |
| 2026-08-04 | 224K | 564K | 39.8% | 22 |
| 2026-08-03 | 158K | 338K | 46.7% | 73 |
| 2026-07-31 | 210K | 466K | 45.1% | 40 |
Fails to deliver
SEC, by settlement date. JSONAs of 7 August 2026, the fails-to-deliver balance in BIIB is 135 shares, down 2,212 shares over the last settlement date. Over the last 48 readings it ranged from 1 share (30 January 2026) to 20,166 shares (14 April 2026). The latest reading sits at the bottom of that range.
| Settlement | Shares failed | Price | Value |
|---|---|---|---|
| 2026-08-07 | 135 | $206.28 | $28K |
| 2026-08-03 | 2,347 | $202.95 | $476K |
| 2026-07-17 | 8 | $208.92 | $2K |
| 2026-07-16 | 63 | $197.24 | $12K |
| 2026-06-30 | 2,785 | $216.63 | $603K |
| 2026-06-29 | 165 | $216.03 | $36K |
| 2026-06-25 | 215 | $199.59 | $43K |
| 2026-06-22 | 2,157 | $196.58 | $424K |
| 2026-06-15 | 692 | $200.05 | $138K |
| 2026-06-03 | 104 | $188.83 | $20K |
| 2026-04-30 | 16 | $194.38 | $3K |
| 2026-04-17 | 122 | $176.02 | $21K |
| 2026-04-16 | 153 | $180.54 | $28K |
| 2026-04-14 | 20,166 | $176.37 | $3.6M |
| 2026-03-27 | 269 | $191.06 | $51K |
| 2026-03-25 | 15 | $183.94 | $3K |
| 2026-03-23 | 285 | $181.46 | $52K |
| 2026-03-18 | 1,146 | $185.29 | $212K |
| 2026-03-17 | 1,077 | $183.26 | $197K |
| 2026-03-06 | 3 | $188.08 | $564 |
| 2026-02-24 | 227 | $196.34 | $45K |
| 2026-02-23 | 1,300 | $192.03 | $250K |
| 2026-02-18 | 4,420 | $195.62 | $865K |
| 2026-02-13 | 28 | $195.50 | $5K |
| 2026-02-12 | 1,017 | $191.20 | $194K |
| 2026-02-10 | 916 | $193.81 | $178K |
| 2026-02-09 | 30 | $201.18 | $6K |
| 2026-01-30 | 1 | $176.18 | $176 |
| 2026-01-16 | 222 | $168.57 | $37K |
| 2026-01-05 | 79 | $177.82 | $14K |
Insider trades
SEC Form 4, newest first, 50 of 92 shown. JSONInsiders at BIIB reported 2 open-market sells worth $240K in the last 90 days and no open-market buys. Sells alone are a weak signal; insiders sell for tax, diversification and estate reasons all the time. Latest filing: Minor Lloyd on 2026-08-04.
| Date | Insider | Title | Type | Shares | Price | Value | Owned after |
|---|---|---|---|---|---|---|---|
| 2026-08-04 | Minor Lloyd | n/a | Sell | 593 | $200.96 | $119K | 3K |
| 2026-08-03 | Minor Lloyd | n/a | Sell | 593 | $203.34 | $121K | 3K |
| 2026-06-09 | HAWKINS WILLIAM A | n/a | Grant | 2K | $0.00 | $0 | 10K |
| 2026-06-09 | SHERWIN STEPHEN A | n/a | Grant | 2K | $0.00 | $0 | 15K |
| 2026-06-09 | Rowinsky Eric K | n/a | Grant | 2K | $0.00 | $0 | 26K |
| 2026-06-09 | Mantas Jesus B | n/a | Grant | 2K | $0.00 | $0 | 11K |
| 2026-06-09 | LANGER SUSAN | n/a | Grant | 2K | $0.00 | $0 | 7K |
| 2026-06-09 | Patolawala Monish D | n/a | Grant | 2K | $0.00 | $0 | 5K |
| 2026-06-09 | Pangalos Menelas N | n/a | Grant | 2K | $0.00 | $0 | 4K |
| 2026-06-09 | Pangalos Menelas N | n/a | Option exercise | 2K | $0.00 | $0 | 2K |
| 2026-06-09 | Minor Lloyd | n/a | Grant | 2K | $0.00 | $0 | 4K |
| 2026-06-09 | Freire Maria C | n/a | Grant | 2K | $0.00 | $0 | 9K |
| 2026-05-01 | Keeney Adam | Head of Corporate Development | Tax withholding | 455 | $187.06 | $85K | 6K |
| 2026-05-01 | Keeney Adam | Head of Corporate Development | Option exercise | 939 | $0.00 | $0 | 7K |
| 2026-04-01 | Godbout Sean | Chief Accounting Officer | Tax withholding | 54 | $183.78 | $10K | 1K |
| 2026-04-01 | Godbout Sean | Chief Accounting Officer | Option exercise | 181 | $0.00 | $0 | 1K |
| 2026-02-12 | Murphy Nicole | Head of Pharm Ops and Tech | Buy | 3 | $195.03 | $585 | 20K |
| 2026-02-09 | Singhal Priya | Head of Development | Sell | 3K | $199.83 | $532K | 8K |
| 2026-02-06 | Viehbacher Christopher | President and CEO | Tax withholding | 7K | $201.18 | $1.3M | 30K |
| 2026-02-06 | Viehbacher Christopher | President and CEO | Option exercise | 15K | $0.00 | $0 | 37K |
| 2026-02-06 | Viehbacher Christopher | President and CEO | Tax withholding | 4K | $201.18 | $876K | 21K |
| 2026-02-06 | Viehbacher Christopher | President and CEO | Option exercise | 9K | $0.00 | $0 | 25K |
| 2026-02-06 | Singhal Priya | Head of Development | Tax withholding | 1K | $201.18 | $284K | 11K |
| 2026-02-06 | Singhal Priya | Head of Development | Option exercise | 5K | $0.00 | $0 | 12K |
| 2026-02-06 | Singhal Priya | Head of Development | Tax withholding | 1K | $201.18 | $212K | 7K |
| 2026-02-06 | Singhal Priya | Head of Development | Option exercise | 2K | $0.00 | $0 | 8K |
| 2026-02-06 | Murphy Nicole | Head of Pharm Ops and Tech | Tax withholding | 1K | $201.18 | $283K | 20K |
| 2026-02-06 | Murphy Nicole | Head of Pharm Ops and Tech | Option exercise | 5K | $0.00 | $0 | 21K |
| 2026-02-06 | Murphy Nicole | Head of Pharm Ops and Tech | Tax withholding | 914 | $201.18 | $184K | 16K |
| 2026-02-06 | Murphy Nicole | Head of Pharm Ops and Tech | Option exercise | 2K | $0.00 | $0 | 17K |
| 2026-02-06 | Murphy Nicole | Head of Pharm Ops and Tech | Tax withholding | 1K | $201.18 | $205K | 15K |
| 2026-02-06 | Murphy Nicole | Head of Pharm Ops and Tech | Option exercise | 2K | $0.00 | $0 | 16K |
| 2026-02-06 | Kramer Robin | Chief Financial Officer | Tax withholding | 1K | $201.18 | $214K | 11K |
| 2026-02-06 | Kramer Robin | Chief Financial Officer | Option exercise | 4K | $0.00 | $0 | 13K |
| 2026-02-06 | Kramer Robin | Chief Financial Officer | Tax withholding | 207 | $201.18 | $42K | 9K |
| 2026-02-06 | Kramer Robin | Chief Financial Officer | Option exercise | 703 | $0.00 | $0 | 9K |
| 2026-02-06 | Kramer Robin | Chief Financial Officer | Tax withholding | 273 | $201.18 | $55K | 9K |
| 2026-02-06 | Kramer Robin | Chief Financial Officer | Option exercise | 789 | $0.00 | $0 | 9K |
| 2026-02-06 | Keeney Adam | Head of Corporate Development | Tax withholding | 994 | $201.18 | $200K | 6K |
| 2026-02-06 | Keeney Adam | Head of Corporate Development | Option exercise | 3K | $0.00 | $0 | 7K |
| 2026-02-06 | Keeney Adam | Head of Corporate Development | Tax withholding | 589 | $201.18 | $118K | 4K |
| 2026-02-06 | Keeney Adam | Head of Corporate Development | Option exercise | 2K | $0.00 | $0 | 4K |
| 2026-02-06 | Izzar Rachid | Head of Global Product Strat. | Tax withholding | 775 | $201.18 | $156K | 11K |
| 2026-02-06 | Izzar Rachid | Head of Global Product Strat. | Option exercise | 3K | $0.00 | $0 | 12K |
| 2026-02-06 | Izzar Rachid | Head of Global Product Strat. | Tax withholding | 458 | $201.18 | $92K | 9K |
| 2026-02-06 | Izzar Rachid | Head of Global Product Strat. | Option exercise | 2K | $0.00 | $0 | 9K |
| 2026-02-06 | Izzar Rachid | Head of Global Product Strat. | Tax withholding | 805 | $201.18 | $162K | 7K |
| 2026-02-06 | Izzar Rachid | Head of Global Product Strat. | Option exercise | 2K | $0.00 | $0 | 8K |
| 2026-02-06 | Grogan Jane | Head of Research | Tax withholding | 584 | $201.18 | $117K | 4K |
| 2026-02-06 | Grogan Jane | Head of Research | Option exercise | 2K | $0.00 | $0 | 5K |
Form 4 filings are due within two business days of the trade. Insiders sell for many reasons that say nothing about the company; open-market buys are the rarer, stronger signal.
Planned sales (Form 144)
Newest first. JSON2 Form 144 notices on file for BIIB worth $240K at the prices reported; 2 in the last 90 days worth $240K. Latest: Minor Lloyd filed on 2026-08-04 to sell 593 shares ($119K) from 2026-08-04.
| Filed | Seller | Shares | Market value | Of outstanding | Sale from | Broker |
|---|---|---|---|---|---|---|
| 2026-08-04 | Minor LloydDirector | 593 | $119K | 0.000% | 2026-08-04 | Fidelity Brokerage Services LLC |
| 2026-08-03 | Minor LloydDirector | 593 | $121K | 0.000% | 2026-08-03 | Fidelity Brokerage Services LLC |
Large holders (13D and 13G)
One row per reporting person, newest filing first. JSON2 holders above 5% have filed on BIIB, all on Schedule 13G (passive). The largest reported stake is FMR LLC at 12.4% of the class (18,294,524 shares), filed 2026-08-06 for an event on 2026-06-30.
| Filed | Form | Holder | Shares | Of class | Event |
|---|---|---|---|---|---|
| 2026-08-06 | 13G/Ano. 3 | FMR LLCparent holding company | 18.3M | 12.4% | 2026-06-30 |
| 2026-08-06 | 13G/Ano. 3 | Abigail P. Johnsonindividual | 18.3M | 12.4% | 2026-06-30 |
13F holders
Tracked managers holding BIIB at their latest 13F. JSON8 of the 30 tracked managers held BIIB at their latest 13F, $743.1M in total at quarter-end prices. AQR Capital Management is the largest at $416.9M (0.1% of its portfolio) as of 2026-06-30. Over the prior quarter 4 added shares and 4 cut.
| Fund | Quarter | Shares | Value | Of portfolio | Change in shares |
|---|---|---|---|---|---|
| AQR Capital Management | 2026-06-30 | 1.9M | $416.9M | 0.15% | +13K |
| Citadel Advisors | 2026-06-30 | 868K | $187.4M | 0.02% | +337K |
| Fisher Asset Management | 2026-06-30 | 338K | $73.0M | 0.02% | +25K |
| Point72 Asset Management | 2026-06-30 | 89K | $19.2M | 0.02% | -726K |
| D. E. Shaw & Co. | 2026-06-30 | 81K | $17.5M | 0.01% | +59K |
| Renaissance Technologies | 2026-06-30 | 78K | $16.8M | 0.02% | -126K |
| Millennium Management | 2026-06-30 | 50K | $10.7M | 0.00% | -506K |
| Two Sigma Investments | 2026-06-30 | 7K | $1.5M | 0.00% | -2K |
Only the 30 tracked managers on the funds hub; a 13F reports long positions in US listed stock at quarter end, 45 days late, and says nothing about shorts or positions sold since.
Financials
SEC XBRL, as filed. JSONIn Q1 2026 (quarter ended 2026-03-31) BIOGEN INC. reported revenue of $2.48B, up 1.9% from the same quarter a year earlier, and net income of $319.5M (2.15 diluted EPS). In FY 2025 it generated $2.20B of operating cash flow.
- Debt
- $6.29B
- Total assets
- $29.48B
- Shares outstanding
- 147,637,117
Quarterly, last 8 quarters
| Quarter | Period end | Revenue | Net income | Margin | Diluted EPS |
|---|---|---|---|---|---|
| Q1 2026 | 2026-03-31 | $2.48B | $319.5M | 12.9% | 2.15 |
| Q4 2025derived | 2025-12-31 | $2.28B | n/a | n/a | n/a |
| Q3 2025 | 2025-09-30 | $2.53B | $466.5M | 18.4% | 3.17 |
| Q2 2025 | 2025-06-30 | $2.65B | $634.8M | 24.0% | 4.33 |
| Q1 2025 | 2025-03-31 | $2.43B | $240.5M | 9.9% | 1.64 |
| Q4 2024derived | 2024-12-31 | $2.45B | n/a | n/a | n/a |
| Q3 2024 | 2024-09-30 | $2.47B | $388.5M | 15.8% | 2.66 |
| Q2 2024 | 2024-06-30 | $2.46B | $583.6M | 23.7% | 4.00 |
Fiscal years, with buybacks and dividends
| Fiscal year | Ends | Revenue | Net income | Operating cash flow | Capex | Buybacks | Dividends |
|---|---|---|---|---|---|---|---|
| FY 2025 | 2025-12-31 | $9.89B | n/a | $2.20B | $153.8M | n/a | n/a |
| FY 2024 | 2024-12-31 | $9.68B | n/a | $2.88B | $153.7M | $0 | n/a |
| FY 2023 | 2023-12-31 | $9.84B | n/a | $1.55B | $277.0M | $0 | n/a |
| FY 2022 | 2022-12-31 | $10.17B | n/a | $1.38B | $240.3M | $750.0M | n/a |
| FY 2021 | 2021-12-31 | $10.98B | n/a | $3.64B | $258.1M | $1.80B | n/a |
Quarters are the three-month figures the company reports; a fourth quarter marked derived is the fiscal year less the three reported quarters, since companies report it only inside the 10-K. Fiscal years are the annual figures. Buybacks are cash paid to repurchase common stock in the year (XBRL PaymentsForRepurchaseOfCommonStock), not authorizations. Balance sheet lines are as of 2026-03-31; shares outstanding as of 2026-04-27 from the cover page.
What this page is
BIOGEN INC. in the regulatory record
Regulators publish company data in separate files that never sit next to each other: FINRA's twice-monthly short interest, its daily short sale volume, the SEC's fails-to-deliver counts, and each insider's Form 4. A company page pulls every series the site collects for one ticker onto one URL, keyed by the SEC's own ticker list, so the short position, the daily flow, the settlement fails and what insiders are doing can be read together.
Each section has its own history table, a summary sentence built from the rows (last value, change, range with dates) and its own JSON and CSV links. Nothing on the page is written by a model; the sentences change only when the data does. A page exists only for companies with data in at least two series, and every section says when its source last updated.
This page follows BIOGEN INC. (BIIB), SEC CIK 875045, listed on Nasdaq, classified by the SEC as biological products, (no diagnostic substances). The cross-market tables live on the short interest and insider transactions hubs.
Source and method
- Short interest
- FINRA consolidated short interestTwice a month, about eight business days after settlement. Latest 2026-08-14.JSON and CSV
- Daily short volume
- FINRA Reg SHO daily filesEvery trading day, loaded the following morning. Latest 2026-09-11.JSON and CSV
- Fails to deliver
- SEC fails-to-deliver dataTwice a month, a few weeks after the half month ends. Latest 2026-08-07.JSON and CSV
- Planned sales
- SEC EDGAR Form 144EDGAR read every 30 minutes; a notice is filed on or before the sell order. Latest 2026-08-04.JSON and CSV
- Large holders
- SEC EDGAR Schedule 13D and 13GEDGAR read every 30 minutes; 13D within five business days of crossing 5%, 13G on the passive schedule. Latest 2026-08-06.JSON and CSV
- 13F holders
- SEC EDGAR Form 13F-HRQuarterly, filed within 45 days of quarter end; 30 tracked managers. Latest 2026-06-30.JSON and CSV
- Financials
- SEC XBRL company factsRefreshed weekly from the SEC's structured data; values are as filed in the 10-Q and 10-K. Latest 2026-03-31.JSON and CSV
- Insider trades
- SEC EDGAR Form 4EDGAR read every 30 minutes; filings are due two business days after the trade. Latest 2026-08-04.JSON and CSV
- Company record
- EDGAR filing index for CIK 875045Ticker, name and exchange from the SEC's company list, refreshed weekly.
- Rate limits
- 30 requests a minute without a key, 120 a minute with a key from a free account.
Data checks. Every dataset is checked against its source once a day. This dataset passed the last run, 13 Sep 05:40 UTC.
How to read it
- Read the position against the flow: rising short interest with a high daily short share is new shorting; rising short interest with a normal short share is old shorts holding on.
- Insider buys next to a crowded short are the combination that has historically preceded squeezes; insider sells next to a crowded short are common and mean little.
- Fails to deliver matter relative to the float, not in absolute shares; a million failed shares in a mega cap is noise.
Analysis of what the data shows, not advice. XOOMAR does not recommend buying, selling or holding anything.
Other companies the SEC classifies as biological products, (no diagnostic substances)
- KYMRKymera Therapeutics, Inc.
- ADPTAdaptive Biotechnologies Corp
- TWSTTwist Bioscience Corp
- HALOHALOZYME THERAPEUTICS, INC.
- KRYSKrystal Biotech, Inc.
- NBIXNEUROCRINE BIOSCIENCES INC
- RVMDRevolution Medicines, Inc.
- AMGNAMGEN INC
- MAZEMaze Therapeutics, Inc.
- GILDGILEAD SCIENCES, INC.
- RXRXRECURSION PHARMACEUTICALS, INC.
- APGEApogee Therapeutics, Inc.
- FENCFENNEC PHARMACEUTICALS INC.
- PCVXVaxcyte, Inc.
- VORVor Biopharma Inc.
- EXELEXELIXIS, INC.
- SRRKScholar Rock Holding Corp
- ADMAADMA BIOLOGICS, INC.
- VCELVericel Corp
- TECHBIO-TECHNE Corp
- ARTVArtiva Biotherapeutics, Inc.
- BCRXBIOCRYST PHARMACEUTICALS INC
- VIRVir Biotechnology, Inc.
- IOVAIOVANCE BIOTHERAPEUTICS, INC.
Datasets
Frequently Asked Questions
How much of BIIB is sold short?
What is BIIB's daily short volume?
Does BIIB have fails to deliver?
Are BIIB insiders buying or selling?
Have BIIB insiders filed to sell?
Who owns more than 5% of BIIB?
What did BIIB report last quarter?
Which funds hold BIIB?
Data on this page is provided for informational purposes only and is not financial advice. See our editorial policy.