Biogen Ownership

Who are the major shareholders and have insiders been buying or selling?

Recent Insider Transactions

SWX:BIIB Recent Insider Transactions by Companies or Individuals
Date	Value	Name	Entity	Role	Shares	Max Price
12 Feb 26	BuyCHF 450	Nicole Murphy	Individual		3	CHF 150.00
08 Jul 25	SellCHF 239,232	Rachid Izzar	Individual		2,223	CHF 107.62

Insider Trading Volume

Insider Buying: Insufficient data to determine if insiders have bought more shares than they have sold in the past 3 months.

Ownership Breakdown

What is the ownership structure of BIIB?
Owner Type	Number of Shares	Ownership Percentage
State or Government	154,413	0.105%
Individual Insiders	305,575	0.207%
General Public	4,363,649	2.96%
Institutions	142,813,480	96.7%

Dilution of Shares: Shareholders have not been meaningfully diluted in the past year.

Top Shareholders

Top 25 shareholders own 68.24% of the company

Ownership	Name	Shares	Current Value	Change %	Portfolio %
10.8%	BlackRock, Inc.	15,973,329	CHF 2.5b	7.86%	0.04%
10.4%	FMR LLC	15,412,560	CHF 2.4b	33.2%	0.13%
10%	PRIMECAP Management Company	14,757,607	CHF 2.3b	0%	1.69%
6.46%	Vanguard Capital Management, LLC	9,537,417	CHF 1.5b	0%	0.03%
4.86%	State Street Global Advisors, Inc.	7,167,922	CHF 1.1b	0.12%	0.04%
4.42%	Vanguard Portfolio Management, LLC	6,531,727	CHF 1.0b	0%	0.06%
2.94%	Geode Capital Management, LLC	4,342,602	CHF 672.8m	3.41%	0.04%
2.01%	Wellington Management Group LLP	2,961,641	CHF 458.9m	-16.6%	0.09%
1.79%	Norges Bank Investment Management	2,638,834	CHF 408.9m	0%	0.03%
1.29%	UBS Asset Management AG	1,901,018	CHF 294.5m	-6.5%	0.02%
1.27%	AQR Capital Management, LLC	1,873,057	CHF 290.2m	25%	0.15%
1.24%	T. Rowe Price Group, Inc.	1,833,416	CHF 284.1m	-6.6%	0.03%
1.15%	Boston Partners Global Investors, Inc.	1,700,078	CHF 263.4m	-1.19%	0.18%
0.98%	Invesco Capital Management LLC	1,449,924	CHF 224.7m	4.48%	0.07%
0.98%	Northern Trust Global Investments	1,446,579	CHF 224.1m	0.03%	0.03%
0.91%	Legal & General Investment Management Limited	1,349,832	CHF 209.1m	-7.52%	0.05%
0.84%	Strategic Advisers LLC	1,240,415	CHF 192.2m	0%	0.06%
0.83%	Eaton Vance Management	1,219,936	CHF 189.0m	2.57%	0.04%
0.81%	JP Morgan Asset Management	1,188,923	CHF 184.2m	-2.64%	0.02%
0.78%	Charles Schwab Investment Management, Inc.	1,149,394	CHF 178.1m	0.48%	0.03%
0.73%	Van Eck Associates Corporation	1,079,861	CHF 167.3m	1.34%	0.11%
0.73%	Dimensional Fund Advisors LP	1,079,119	CHF 167.2m	12.3%	0.02%
0.7%	Deutsche Asset & Wealth Management	1,029,793	CHF 159.6m	11.9%	0.04%
0.65%	Bank of America Corporation	964,427	CHF 149.4m	4.02%	0.04%
0.62%	Goldman Sachs Asset Management, L.P.	918,051	CHF 142.2m	-2.45%	0.03%

Company Analysis and Financial Data Status

Data	Last Updated (UTC time)
Company Analysis	2026/06/17 21:14
End of Day Share Price	2026/03/20 00:00
Earnings	2026/03/31
Annual Earnings	2025/12/31

Data Sources

The data used in our company analysis is from S&P Global Market Intelligence LLC. The following data is used in our analysis model to generate this report. Data is normalised which can introduce a delay from the source being available.

Package	Data	Timeframe	Example US Source ^*
Company Financials	10 years	Income statement Cash flow statement Balance sheet	SEC Form 10-K SEC Form 10-Q
Analyst Consensus Estimates	+3 years	Forecast financials Analyst price targets	Analyst Research Reports Blue Matrix
Market Prices	30 years	Stock prices Dividends, Splits and Actions	ICE Market Data SEC Form S-1
Ownership	10 years	Top shareholders Insider trading	SEC Form 4 SEC Form 13D
Management	10 years	Leadership team Board of directors	SEC Form 10-K SEC Form DEF 14A
Key Developments	10 years	Company announcements	SEC Form 8-K

^* Example for US securities, for non-US equivalent regulatory forms and sources are used.

Unless specified all financial data is based on a yearly period but updated quarterly. This is known as Trailing Twelve Month (TTM) or Last Twelve Month (LTM) Data. Learn more.

Analysis Model and Snowflake

Details of the analysis model used to generate this report is available on our Github page, we also have guides on how to use our reports and tutorials on Youtube.

Learn about the world class team who designed and built the Simply Wall St analysis model.

Industry and Sector Metrics

Our industry and section metrics are calculated every 6 hours by Simply Wall St, details of our process are available on Github.

Analyst Sources

Biogen Inc. is covered by 58 analysts. 22 of those analysts submitted the estimates of revenue or earnings used as inputs to our report. Analysts submissions are updated throughout the day.

Analyst	Institution
David Toung	Argus Research Company
Brian Skorney	Baird
Emily Field	Barclays