BIIB SEC Filing News — Biogen Inc.

Q: What is the difference between a 10-K and 10-Q for BIIB?

The 10-K is Biogen Inc.'s annual report with fully audited financial statements, comprehensive MD&A, and complete risk factor disclosures — filed 60–90 days after fiscal year-end. The 10-Q is a lighter quarterly report with unaudited financials filed for the first three quarters. Together they provide a continuous financial picture of the company.

Latest SEC filings for Biogen Inc. (BIIB) explained in plain English. Covers insider buying and selling (Form 4), proposed insider sales (Form 144), material company events (8-K), and quarterly & annual reports (10-Q / 10-K). StrongBuyAnalytics provides navigation and brief excerpts or summaries; original filings remain at the SEC/source links and were authored by their filers, not StrongBuyAnalytics. Filing dates shown are source dates. Coverage and detection can be delayed or incomplete because of SEC availability, amendments, parsing, caching, or outages. Latest source filing date shown: 2026-10-05.

Biogen Inc. discovers, develops, manufactures, and delivers therapies in the United States, Europe, Germany, Asia, and internationally. The company provides TECFIDERA, VUMERITY, AVONEX, PLEGRIDY, and TYSABRI for multiple sclerosis (MS); SPINRAZA for spinal muscular atrophy; SKYCLARYS to treat Friedreich's Ataxia; QALSODY for treating amyotrophic lateral sclerosis; FUMADERM to treat plaque psoriasis; BENEPALI, an etanercept biosimilar referencing ENBREL; IMRALDI, an adalimumab biosimilar referenc…

Sector: Healthcare Industry: Drug Manufacturers - General Market Cap: $33.0B CIK: 875045

Total Filings

Bullish Classifications

Bearish Classifications

Insider Transactions

Material Events (8-K)

Periodic Reports

Rule-based classifications for BIIB currently lean bearish. Of the 20 filing records displayed, 1 carry bearish classifications (such as insider sales or negative 8-K disclosures) versus 0 bullish. This does not necessarily signal fundamental deterioration — insiders sell for many reasons — but it is worth monitoring alongside the company's core financial metrics.

BIIB Filing Activity Snapshot 2026-05-14 — 2026-10-05

Insider Transactions (Form 4)

0 buys vs 1 sell

Net insider selling in this period — insiders sell for many reasons beyond conviction.

Largest Form 144 Filing

$239.7K

Minor Lloyd (Director) · 2026-08-05

1,186 shares · Form 4

Form 144 Notices

Proposed insider sales filed — Form 144 is a notice of intent, not a confirmed transaction. Actual sales are confirmed via Form 4.

Insider Transactions 12 · Forms 3, 4 and 5

A Form 4 is filed within two business days of a company insider — an officer, a director, or a holder of more than ten percent of the stock — changing their position in the shares. All 12 filings in this group are Form 4s for Biogen Inc.

The difficulty with reading these filings as a group is that a single form type covers transactions that mean entirely different things. An executive spending their own money to buy stock and an executive having shares withheld to pay tax on a vesting grant both appear as a Form 4. Every filing below is therefore tagged with the nature of the underlying transaction, taken from the transaction code reported on the form itself.

Across the 12 insider filings shown, the breakdown is 11 compensation award and 1 open-market sale. 1 of them involved a discretionary open-market trade; the rest are compensation and administrative mechanics.

What each transaction type means

Compensation award ×11: Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.
Open-market sale ×1: The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.

Form 4 Compensation award Tax / Compensation Filing 2026-10-05

BIIB insider Form 4 filed for equity award, exercise, or tax withholding

Godbout Sean (Chief Accounting Officer) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`M`	Option exercise	27	—	—
`F`	Tax withholding on vested shares	8	$219.88	$1.8K
`A`	Compensation award derivative · Restricted Stock Unit	985	—	—
`M`	Option exercise derivative · Restricted Stock Unit	27	—	—

Filing: Form 4 (Insider Transaction) Insider: Godbout Sean (Chief Accounting Officer) Shares: 35

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-09-03

BIIB insider Form 4 filed for equity award, exercise, or tax withholding

Parini Michael (Chief Legal Officer) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`A`	Compensation award derivative · Restricted Stock Unit	7,405	—	—

Filing: Form 4 (Insider Transaction) Insider: Parini Michael (Chief Legal Officer)

View on SEC EDGAR → Open Filing Document →

Form 4 Open-market sale Insider Selling 2026-08-05

BIIB insider Minor Lloyd (Director) sold 1,186 shares (~$239.7K)

Minor Lloyd, listed as Director at BIOGEN INC., reported an open-market sale of 1,186 BIIB shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.

The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`S`	Open-market sale	593	$203.34	$120.6K
`S`	Open-market sale	593	$200.96	$119.2K

Filing: Form 4 (Insider Transaction) Insider: Minor Lloyd (Director) Shares: 1,186 Est. Value: $239.7K

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-06-11

BIIB insider Form 4 filed for equity award, exercise, or tax withholding

HAWKINS WILLIAM A (Director) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`A`	Compensation award	1,505	—	—

Filing: Form 4 (Insider Transaction) Insider: HAWKINS WILLIAM A (Director) Shares: 1,505

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-06-11

BIIB insider Form 4 filed for equity award, exercise, or tax withholding

SHERWIN STEPHEN A (Director) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`A`	Compensation award	1,505	—	—

Filing: Form 4 (Insider Transaction) Insider: SHERWIN STEPHEN A (Director) Shares: 1,505

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-06-11

BIIB insider Form 4 filed for equity award, exercise, or tax withholding

Rowinsky Eric K (Director) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`A`	Compensation award	1,505	—	—

Filing: Form 4 (Insider Transaction) Insider: Rowinsky Eric K (Director) Shares: 1,505

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-06-11

BIIB insider Form 4 filed for equity award, exercise, or tax withholding

Mantas Jesus B (Director) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`A`	Compensation award	1,505	—	—

Filing: Form 4 (Insider Transaction) Insider: Mantas Jesus B (Director) Shares: 1,505

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-06-11

BIIB insider Form 4 filed for equity award, exercise, or tax withholding

LANGER SUSAN (Director) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`A`	Compensation award	1,505	—	—

Filing: Form 4 (Insider Transaction) Insider: LANGER SUSAN (Director) Shares: 1,505

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-06-11

BIIB insider Form 4 filed for equity award, exercise, or tax withholding

Patolawala Monish D (Director) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`A`	Compensation award	1,505	—	—

Filing: Form 4 (Insider Transaction) Insider: Patolawala Monish D (Director) Shares: 1,505

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-06-11

BIIB insider Form 4 filed for equity award, exercise, or tax withholding

Pangalos Menelas N (Director) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`M`	Option exercise	2,370	—	—
`A`	Compensation award	1,505	—	—
`M`	Option exercise derivative · Restricted Stock Unit	2,370	—	—

Filing: Form 4 (Insider Transaction) Insider: Pangalos Menelas N (Director) Shares: 3,875

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-06-11

BIIB insider Form 4 filed for equity award, exercise, or tax withholding

Minor Lloyd (Director) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`A`	Compensation award	1,505	—	—

Filing: Form 4 (Insider Transaction) Insider: Minor Lloyd (Director) Shares: 1,505

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-06-11

BIIB insider Form 4 filed for equity award, exercise, or tax withholding

Freire Maria C (Director) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`A`	Compensation award	2,005	—	—

Filing: Form 4 (Insider Transaction) Insider: Freire Maria C (Director) Shares: 2,005

View on SEC EDGAR → Open Filing Document →

Proposed Insider Sales 2 · Form 144

A Form 144 is a notice of intent to sell restricted or control securities. It is not a record that anything was sold. Biogen Inc. has 2 such notices in this period.

The distinction matters because a Form 144 is frequently reported as though it were a completed insider sale. The filer may sell all of the shares covered, some of them, or none at all, and there is no obligation to update the notice either way. A sale that is actually executed by an officer or director shows up separately on a Form 4, which is the filing to check before treating a proposed sale as a real one.

Form 144 Proposed Insider Sale 2026-08-04

BIIB Form 144 filed for proposed insider sale by Minor Lloyd (593 shares) ~$119.2K

Minor Lloyd filed a Form 144 with the SEC indicating intent to sell BIIB (BIOGEN INC.) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: Minor Lloyd Shares: 593 Est. Value: $119.2K

View on SEC EDGAR → Open Filing Document →

Form 144 Proposed Insider Sale 2026-08-03

BIIB Form 144 filed for proposed insider sale by Minor Lloyd (593 shares) ~$120.6K

Filing: Form 144 (Proposed Sale Notice) Insider: Minor Lloyd Shares: 593 Est. Value: $120.6K

View on SEC EDGAR → Open Filing Document →

Material Events 5 · Form 8-K

An 8-K reports a material event in the window between scheduled reports. There are 5 in this period for Biogen Inc. Each 8-K names the item number it is filed under, and that number is the fastest way to tell a routine disclosure from a consequential one.

Item 2.02 is an earnings release, Item 5.02 is a change of directors or officers, and Item 1.01 or 2.01 covers a material agreement or a completed acquisition. Item 7.01 and Item 8.01 are the general-purpose disclosure items and carry no fixed meaning on their own.

Form 8-K Material Company Update 2026-07-29

BIIB filed 8-K — material company event

BIOGEN INC. filed an 8-K with the SEC reporting a material event. Summary unavailable — view the original SEC filing for the full text.

Filing: 8-K (Material Event)

View on SEC EDGAR → Open Filing Document →

Form 8-K Material Company Update 2026-07-01

BIIB filed 8-K — material company event

BIOGEN INC. filed an 8-K with the SEC reporting a material event. Summary unavailable — view the original SEC filing for the full text.

Filing: 8-K (Material Event)

View on SEC EDGAR → Open Filing Document →

Form 8-K Material Company Update 2026-06-10

BIIB filed 8-K — material company event

BIOGEN INC. filed an 8-K with the SEC reporting a material event. Summary unavailable — view the original SEC filing for the full text.

Filing: 8-K (Material Event)

View on SEC EDGAR → Open Filing Document →

Form 8-K/A Amended Material Company Update 2026-06-10

BIIB filed amended 8-K — material company event

BIOGEN INC. filed an amended 8-K with the SEC reporting a material event. Summary unavailable — view the original SEC filing for the full text.

Filing: 8-K/A (Material Event Amendment)

View on SEC EDGAR → Open Filing Document →

Form 8-K Material Company Update 2026-05-14

BIIB filed 8-K — material company event

BIOGEN INC. filed an 8-K with the SEC reporting a material event. Summary unavailable — view the original SEC filing for the full text.

Filing: 8-K (Material Event)

View on SEC EDGAR → Open Filing Document →

Periodic Reports 1 · Forms 10-K and 10-Q

The periodic reports are where the audited and reviewed financial statements live. This period contains 1 quarterly report (10-Q) for Biogen Inc.

The two are not equivalent in weight. A 10-K is audited by an external firm and includes the full risk factor disclosure, business description and management discussion; a 10-Q is unaudited, reviewed rather than examined, and much shorter. When a figure in a quarterly report is later revised, the annual report is usually where the correction appears.

An amended report — 10-K/A or 10-Q/A — restates or corrects something in the original filing, and is worth reading against the version it replaces.

Form 10-Q Quarterly Report 2026-07-29

BIIB filed Quarterly Report (10-Q)

BIOGEN INC. filed its quarterly report with the SEC. This report includes unaudited financial statements and management discussion for the quarter.

Filing: 10-Q (Quarterly Report)

View on SEC EDGAR → Open Filing Document →

How we classify Biogen Inc.'s filings

Straight from EDGAR

Each displayed record links to an original source document. StrongBuyAnalytics provides navigation and brief excerpts or summaries, not the filing itself. Parsing may omit context or contain errors, so read the original document in full.

Transaction codes, not guesswork

The nature shown on each insider filing comes from the transaction code the filer entered on the form itself — P for an open-market purchase, A for a compensation award, F for shares withheld to pay tax, M for an option exercise. Where one filing contains several codes, the transaction table lists them line by line.

Why the distinction matters

Insider activity is routinely summarised as buying or selling, which flattens together decisions that mean very different things. Shares withheld for tax on a vesting grant are an automatic administrative step; shares bought on the open market are someone committing their own money at the current price.

What this page does not tell you

A filing records what happened, not why. Form 4 does not always disclose whether a sale was executed under a pre-arranged Rule 10b5-1 plan, and no single filing is a basis for a decision on BIIB. Read these alongside the fundamentals rather than in isolation.

Frequently Asked Questions — BIIB SEC Filings

What SEC filings does Biogen Inc. submit to the SEC?

Biogen Inc. (BIIB) submits several types of SEC filings including Form 4 (insider transactions), Form 144 (proposed insider sales), 8-K reports (material events such as earnings releases, acquisitions, leadership changes), and periodic reports — the 10-Q (quarterly) and 10-K (annual). All filings are publicly available through SEC EDGAR.

What does a Form 4 filing tell me about BIIB?

A Form 4 for BIIB discloses a transaction by a company insider — typically a director, officer, or 10%+ shareholder. It shows the source-reported date, number of shares, price, and updated ownership. These facts do not establish motive or predict future returns.

How do I interpret an 8-K filing from Biogen Inc.?

An 8-K signals a material event requiring prompt disclosure. Common triggers include earnings pre-announcements, acquisitions, leadership appointments or departures, credit changes, or regulatory actions. Read the item codes inside the filing to understand exactly what was disclosed before drawing conclusions.

What is the difference between a 10-K and 10-Q for BIIB?

The 10-K is Biogen Inc.'s annual report with fully audited financial statements, comprehensive MD&A, and complete risk factor disclosures — filed 60–90 days after fiscal year-end. The 10-Q is a lighter quarterly report with unaudited financials filed for the first three quarters. Together they provide a continuous financial picture of the company.

Where can I see all BIIB SEC filings directly on EDGAR?

You can view all historical Biogen Inc. filings on the SEC EDGAR company page for BIIB. Each filing card on this page links directly to the original SEC document.

How often does Biogen Inc. file with the SEC?

Biogen Inc. files one 10-K per year and up to three 10-Qs per year. Form 4 insider transactions must be reported within two business days of each trade, so the frequency depends on how often insiders are buying or selling BIIB shares. 8-K filings occur whenever a material event happens — which can be several times per quarter for an active company.

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BIIB Full Analysis

Publisher, sources & limitations — September 15, 2026. StrongBuyAnalytics provides navigation and brief excerpts or summaries for educational use. Original filings remain at SEC EDGAR or other displayed source links; StrongBuyAnalytics does not author them. Filing dates are source dates, not publication dates for this page. Coverage can be delayed, incomplete, amended, or unavailable because of SEC/source availability, parsing, caching, or outages. Verify every material statement in the original filing.

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