Stocks / BIIB / Shares Outstanding

Biogen Inc. Shares Outstanding 2007–2025

Biogen Inc. reported 146.8M of shares outstanding for fiscal 2025. That was 0.7% higher than fiscal 2024. Compared with fiscal 2020, the change was -3.7%. A rising share count can dilute per-share ownership; the filings should be checked for issuance and stock-compensation details.

Latest filed value
146.8M
One-year change
+0.7%
Change since 2020
-3.7%
Latest period end
2025-12-31
Biogen Inc. Shares Outstanding history from 2007 to 2025FY 2007: 0FY 2008: 288046000FY 2009: 274855FY 2010: 240538000FY 2011: 242115000FY 2012: 236582000FY 2013: 236332000FY 2014: 234600000FY 2015: 218600000FY 2016: 215900000FY 2017: 211500000FY 2018: 197200000FY 2019: 174200000FY 2020: 152400000FY 2021: 147000000FY 2022: 144000000FY 2023: 144900000FY 2024: 145800000FY 2025: 146800000
Annual filed history. Hover chart points for raw values; the accessible table below is the source of record.
Fiscal yearShares OutstandingChange (YoY)
FY 2025146.8M+0.7%
FY 2024145.8M+0.6%
FY 2023144.9M+0.6%
FY 2022144.0M-2.0%
FY 2021147.0M-3.5%
FY 2020152.4M-12.5%
FY 2019174.2M-11.7%
FY 2018197.2M-6.8%
FY 2017211.5M-2.0%
FY 2016215.9M-1.2%
FY 2015218.6M-6.8%
FY 2014234.6M-0.7%
FY 2013236.3M-0.1%
FY 2012236.6M-2.3%
FY 2011242.1M+0.7%
FY 2010240.5M+87414.5%
FY 20090.3M-99.9%
FY 2008288.0M
FY 20070.0M

Source: Biogen Inc. SEC filings — balance sheet (10-K), split-adjusted. Computed deterministically; refreshed nightly (last updated August 2, 2026). Open BIIB 10-K filings at SEC EDGAR · Methodology · Download CSV.

How to read this history

Biogen Inc. reported 146.8M of shares outstanding for fiscal 2025. That was 0.7% higher than fiscal 2024. Compared with fiscal 2020, the change was -3.7%. A rising share count can dilute per-share ownership; the filings should be checked for issuance and stock-compensation details. Values remain missing when the cached filing does not disclose a comparable line item; they are never estimated. Stock splits, reorganizations and fiscal-calendar changes can reduce comparability.

Prepared and reviewed by the stockportfolio.pro research desk. Corrections: support@stockportfolio.pro.

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Biogen Inc. — frequently asked questions

What is Biogen Inc.'s shares outstanding?

Biogen Inc. (BIIB) reported shares outstanding of 146.8M for fiscal year 2025, per its SEC filings.

Where does this data come from?

Figures are computed from Biogen Inc.'s official SEC filings (balance sheet (10-K), split-adjusted), refreshed nightly. Not investment advice.

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