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$1,000 in Biogen Inc. in 2020 → $747 today

If you'd invested $1,000 in Biogen Inc. (BIIB) on January 1, 2020 — at the December 2019 month-end close of $297 — and held to the latest close (2026-08-), you'd have $747. That's a -25.3% total return — trailing the S&P 500, where the same $1,000 became $2,386.

$1,000 in 2020$747Total return-25.3%Multiple75%CAGR-4.3%

Nearby years: 2016 · 2017 · 2018 · 2019 · 2021 · 2022 · 2023 · 2024 all years →

FAQ

How much is $1,000 invested in BIIB in 2020 worth today?

$1,000 invested in Biogen Inc. (BIIB) at the month-end close of 2019-12- would be worth $747 at the latest month-end close (2026-08-), a total return of -25.3% with dividends reinvested.

Did $1,000 in BIIB in 2020 beat the market?

Over the same span, $1,000 in the S&P 500 index would be worth $2,386 — so Biogen Inc. (BIIB) trailed the index by +68.7%.

What does "month-end close" mean for this calculation?

The scenario invests at the December 2019 month-end close (the price entering 2020) and values the position at the most recent month-end close (2026-08-). Intra-month extremes are shown on the BIIB calculator page.

Is the 2020–2026 return in BIIB typical?

No single year is typical. BIIB's best calendar-year return since 1991 was about +818.1%, and its worst was -63.0%.

Methodology

Biogen Inc. (BIIB) total-return data from January 2020 through the latest month-end close (2026-08-).

The entry price is the 2019 December month-end close and the exit is the latest available month-end close, both from adjusted (split and dividend) Yahoo Finance historical data.

Month-end resolution, no taxes or fees, and history never guarantees the future. For exact-date precision (including buying at a panic low), use the BIIB calculator page.

Full methodology →

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Data: Yahoo Finance. As of 2026-08-. Not financial advice.