Biogen Inc. (BIIB) exec exercises RSUs, uses shares for taxes

Filing Impact

(Neutral)

Filing Sentiment

(Neutral)

Form Type

Rhea-AI Filing Summary

BIOGEN INC. Head of Corporate Development Adam Keeney reported routine equity compensation transactions involving the company’s common stock. On May 1, 2026, 939 restricted stock units were exercised into 939 shares of common stock at a conversion price of $0.00 per share. To cover tax obligations, 455 shares of common stock were disposed of at a price of $187.06 per share as a tax-withholding transaction, not an open-market sale. Following these transactions, Keeney directly owned 6,365 shares of Biogen common stock. The restricted stock units that were exercised were part of an award that vests in three equal yearly installments beginning on the first anniversary of the May 1, 2023 grant date.

Insider Trade Summary

939 shares exercised/converted

Mixed 3 txns

Insider Keeney Adam

Role Head of Corporate Development

Type	Security	Shares	Price	Value
Exercise	Restricted Stock Unit	939	$0.00	--
Exercise	Common Stock	939	$0.00	--
Tax Withholding	Common Stock	455	$187.06	$85K

Holdings After Transaction: Restricted Stock Unit — 0 shares (Direct, null); Common Stock — 6,820 shares (Direct, null)

Footnotes (1)

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Key Figures

RSUs exercised: 939 shares Tax-withholding shares: 455 shares Tax-withholding price: $187.06 per share +2 more

5 metrics

RSUs exercised 939 shares Restricted stock units converted to Biogen common stock on May 1, 2026

Tax-withholding shares 455 shares Shares disposed of to satisfy tax liability at $187.06 per share

Tax-withholding price $187.06 per share Price used for 455-share F-code tax-withholding disposition

Direct holdings after tax transaction 6,365 shares Biogen common stock directly owned by Adam Keeney after disposition

Conversion price for RSUs $0.00 per share Stated conversion/exercise price for 939 restricted stock units

Key Terms

Restricted Stock Unit, tax-withholding disposition, derivative exercise/conversion, transaction code F, +1 more

5 terms

Restricted Stock Unit financial

"The restricted stock units vest in three equal yearly installments"

A restricted stock unit is a promise from a company to give an employee shares of stock after certain conditions are met, like staying with the company for a set amount of time. It’s like earning a bonus that turns into company stock once you’ve proven your commitment, making it a way to motivate and reward employees.

tax-withholding disposition financial

"transaction_action": "tax-withholding disposition""

A tax-withholding disposition is an event or transaction—such as selling or transferring securities, exercising options, or receiving compensation—that triggers a requirement to hold back part of the payment and remit it to tax authorities. It matters to investors because it reduces the cash they receive immediately and can change the timing and amount of taxable income, like a cashier taking a portion of your sale proceeds to pay taxes before you get the rest.

derivative exercise/conversion financial

"transaction_action": "derivative exercise/conversion""

transaction code F financial

"transaction_code": "F""

transaction code M financial

"transaction_code": "M""

Form 4 Insider Transactions: What Each Field Means →

05/05/2026 - 04:11 PM

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Keeney Adam

(Last)

(First)

(Middle)

BIOGEN INC.

225 BINNEY STREET

(Street)

CAMBRIDGE

MASSACHUSETTS

02142

(City)

(State)

(Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
BIOGEN INC. [ BIIB ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director	10% Owner
X	Officer (give title below)	Other (specify below)
	Head of Corporate Development

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/01/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	05/01/2026		M		939	A	$0	6,820	D
Common Stock	05/01/2026		F		455	D	$187.06	6,365	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
Restricted Stock Unit	$0	05/01/2026		M			939	⁽¹⁾	05/01/2026	Common Stock	939	$0	0	D

Explanation of Responses:

1. The restricted stock units vest in three equal yearly installments beginning on the first anniversary of the grant date of May 1, 2023.

	/s/ Wendell Taylor, attorney-in-fact for Mr. Keeney	05/05/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

Source: View Original Filing on SEC EDGAR

FAQ

What insider transaction did Biogen (BIIB) executive Adam Keeney report?

Adam Keeney reported exercising 939 restricted stock units into Biogen common shares and a related tax-withholding share disposition. These actions reflect routine equity compensation mechanics rather than an open-market stock purchase or sale.

How many Biogen (BIIB) shares were exercised and withheld for taxes?

Keeney exercised 939 restricted stock units into 939 shares of Biogen common stock. Of those shares, 455 were disposed of at $187.06 per share to satisfy tax obligations through share withholding, rather than a discretionary market sale.

How many Biogen (BIIB) shares does Adam Keeney hold after this Form 4?

Following the reported transactions, Adam Keeney directly owns 6,365 shares of Biogen common stock. This figure reflects both the 939-share RSU exercise and the 455-share tax-withholding disposition reported for the May 1, 2026 transactions.

What does the M transaction code mean in this Biogen (BIIB) Form 4?

The M code indicates a derivative exercise or conversion. In this case, 939 restricted stock units converted into 939 Biogen common shares at a stated conversion price of $0.00 per share, consistent with vesting of stock-based compensation.

What does the F transaction code signify in Adam Keeney’s Biogen (BIIB) filing?

The F code represents payment of tax liability or exercise price by delivering securities. Keeney’s 455-share disposition at $187.06 per share was used to cover taxes, rather than a discretionary open-market sale for portfolio rebalancing.

How do the restricted stock units in this Biogen (BIIB) filing vest?

The restricted stock units vest in three equal yearly installments beginning on the first anniversary of the grant date of May 1, 2023. The 939 units exercised on May 1, 2026 are part of this multi-year vesting schedule disclosed in the footnote.