Michael R. Mcdonnell - Feb 16, 2024 Form 4 Insider Report for BIOGEN INC. (BIIB)

Role: EVP, Chief Financial Officer
Signature: /s/ Wendell Taylor, attorney-in-fact for Michael R. McDonnell
Stock symbol: BIIB
Transactions as of: Feb 16, 2024
Transactions value $: -$753,197
Form type: 4
Date filed: 2/21/2024, 09:29 PM
Previous filing: Feb 13, 2024
Next filing: May 20, 2024

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership
transaction	BIIB	Common Stock	Options Exercise	$0	+4.57K	+28.33%	$0.00	20.7K	Feb 16, 2024	Direct
transaction	BIIB	Common Stock	Tax liability	-$512K	-2.34K	-11.29%	$219.08	18.4K	Feb 16, 2024	Direct
transaction	BIIB	Common Stock	Options Exercise	$0	+2.15K	+11.72%	$0.00	20.5K	Feb 16, 2024	Direct
transaction	BIIB	Common Stock	Tax liability	-$241K	-1.1K	-5.37%	$219.08	19.4K	Feb 16, 2024	Direct

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	BIIB	Performance Stock Unit	Options Exercise	$0	-4.57K	-100%	$0.00^*	0	Feb 16, 2024	Common Stock	4.57K	$0.00	Direct
transaction	BIIB	Restricted Stock Unit	Options Exercise	$0	-2.15K	-44.5%	$0.00	2.68K	Feb 16, 2024	Common Stock	2.15K	$0.00	Direct	F1
transaction	BIIB	Restricted Stock Unit	Other	$0	-2.68K	-100%	$0.00^*	0	Feb 16, 2024	Common Stock	2.68K	$0.00	Direct	F1, F2

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	This award was granted to the reporting person on February 18, 2021. The number of RSUs reported represented the maximum possible number of shares that were eligible for vesting, which is 200% of the number of shares at target payout. One-third of these RSUs are eligible to vest on each of the first three anniversaries of the grant date. The actual number of shares that will vest on each vesting date will be determined by comparing the price of Biogen common stock on such vesting date to the price on the grant date (i.e., number of vested shares = number of shares at target payout times [the 30-day average closing stock price ending on the vesting date divided by the 30-day average closing stock price following and including the grant date]).
F2	This represents the difference between the maximum possible number of shares that were eligible for vesting and the actual number that vested.

Content

This award was granted to the reporting person on February 18, 2021. The number of RSUs reported represented the maximum possible number of shares that were eligible for vesting, which is 200% of the number of shares at target payout. One-third of these RSUs are eligible to vest on each of the first three anniversaries of the grant date. The actual number of shares that will vest on each vesting date will be determined by comparing the price of Biogen common stock on such vesting date to the price on the grant date (i.e., number of vested shares = number of shares at target payout times [the 30-day average closing stock price ending on the vesting date divided by the 30-day average closing stock price following and including the grant date]).

This represents the difference between the maximum possible number of shares that were eligible for vesting and the actual number that vested.