Biogen has retired 57.1% of its shares since 2005, from 344,098,779 to 147,753,998.
At $232.65 a share, a market value of $34.4B. FCF yield 7.0%, P/E 25.1, trailing twelve months to March 2026.
| Fiscal year | Date | Shares outstanding | Filing | |
|---|---|---|---|---|
| 2003 | 2004-02-20 | 331,996,625 | 10-K | cover page |
| 2004 | 2005-03-10 | 344,027,240 | 10-K | cover page |
| 2005 | 2006-02-01 | 344,098,779 | 10-K | cover page |
| 2006 | 2007-02-15 | 342,436,836 | 10-K | cover page |
| 2007 | 2008-02-08 | 297,750,601 | 10-K | cover page |
| 2008 | 2008-12-31 | 288,046,000 | 10-K | |
| 2009 | 2010-02-05 | 269,601,262 | 10-K | |
| 2010 | 2011-01-31 | 240,911,883 | 10-K | |
| 2011 | 2012-01-31 | 238,725,065 | 10-K | |
| 2012 | 2013-01-31 | 236,312,191 | 10-K | |
| 2013 | 2014-01-31 | 236,393,930 | 10-K | |
| 2014 | 2015-01-30 | 234,614,474 | 10-K | |
| 2015 | 2016-01-29 | 218,672,717 | 10-K | |
| 2016 | 2017-01-27 | 215,951,945 | 10-K | |
| 2017 | 2018-01-26 | 211,562,686 | 10-K | |
| 2018 | 2019-02-01 | 196,708,784 | 10-K | |
| 2019 | 2020-02-04 | 174,064,011 | 10-K | |
| 2020 | 2021-02-02 | 152,335,731 | 10-K | |
| 2021 | 2022-02-02 | 146,962,793 | 10-K | |
| 2022 | 2023-02-14 | 144,485,646 | 10-K | |
| 2023 | 2024-02-12 | 145,360,798 | 10-K | |
| 2024 | 2025-02-11 | 146,374,937 | 10-K | |
| 2025 | 2026-02-04 | 146,758,528 | 10-K |
Source: all 10-K filings of Biogen on EDGAR. Download this series as CSV. Licence CC BY 4.0, credit Buyback Radar.
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Not on a net basis. Biogen has 0.7% more shares outstanding than twelve months ago. Whatever it bought back did not cover the new shares it issued. Over five years the share count is up 0.6%.
Net of every new share it issued, Biogen has 196.3 million fewer shares than at its 2005 peak. That is 57.1% of the company.
147,753,998 shares, as of July 27, 2026, from the cover page of its latest 10-Q. At the 2005 peak it had 344,098,779.
Each share is a bigger slice of the company. Someone who held Biogen stock in 2005 owns 2.3 times as much of the business today without buying another share. Whether that was a good use of cash depends on the price paid.
Biogen ranks No. 55 of 467 companies on Buyback Radar by share of the company retired since its peak. Close to it on the list: Best Buy (57.3%), TJX Companies (57.3%), Star Group (56.7%), Ross Stores (56.4%).
Every answer is computed from Biogen's own SEC filings and rebuilt every Monday. Latest count: 10-Q on EDGAR.
The numbers say what happened. The story says whether it can continue. We cover companies like Biogen in depth on Cannibal Stocks.
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