Biogen (BIIB) Shares Outstanding (Diluted Average) (2009 - 2026)

Biogen's Shares Outstanding (Diluted Average) history runs 18 years deep, the most recent figure standing at $148.4 million for Q1 2026.

• In Q1 2026, Shares Outstanding (Diluted Average) rose 1.23% year-over-year to $148.4 million; the TTM figure through Mar 2026 stood at $148.4 million (up 1.23% YoY), while the FY2025 annual figure was $147.1 million, up 0.82% from the prior year.
• Shares Outstanding (Diluted Average) was $148.4 million for Q1 2026 at Biogen, up from $147.1 million in the prior quarter.
• In the past five years, Shares Outstanding (Diluted Average) ranged from a high of $148.4 million in Q1 2026 to a low of $145.2 million in Q1 2023.
• Historically, Shares Outstanding (Diluted Average) has averaged $146.4 million across 5 years, with a median of $146.1 million in 2024.
• The sharpest annual moves came in 2022 and 2026: Shares Outstanding (Diluted Average) slipped 3.09% in 2022, then gained 1.23% in 2026.
• A 5-year view of Shares Outstanding (Diluted Average) shows it stood at $146.0 million in 2022, then fell by 0.27% to $145.6 million in 2023, then gained by 0.21% to $145.9 million in 2024, then increased by 0.82% to $147.1 million in 2025, then advanced by 0.88% to $148.4 million in 2026.
• The last three Shares Outstanding (Diluted Average) figures came in at $148.4 million (Q1 2026), $147.1 million (Q4 2025), and $147.1 million (Q3 2025), per Business Quant data.