Seasonality
BIIB seasonality — Biogen
Over the last 11 years, BIIB's strongest month on average has been June (+4.0%) and its weakest March (-3.8%).
Average return by month
Month-by-month statistics
| Month | Avg | Median | Up % | Best | Worst | Yrs |
|---|---|---|---|---|---|---|
| Jan | +1.48% | -0.01% | 50% | +15.4% | -9.4% | 10 |
| Feb | -2.49% | -2.91% | 30% | +14.7% | -16.9% | 10 |
| Mar | -3.82% | -1.62% | 30% | +3.0% | -27.9% | 10 |
| Apr | -1.53% | -1.15% | 20% | +9.4% | -11.5% | 10 |
| May | +0.73% | +1.76% | 60% | +7.4% | -8.6% | 10 |
| Jun | +3.96% | +2.51% | 60% | +29.5% | -12.9% | 10 |
| Jul | +0.88% | +1.80% | 60% | +15.2% | -8.0% | 10 |
| Aug | +1.18% | +3.51% | 60% | +9.3% | -9.2% | 10 |
| Sep | +2.46% | -0.57% | 40% | +36.7% | -16.5% | 10 |
| Oct | +0.78% | -3.11% | 40% | +28.3% | -13.9% | 10 |
| Nov | +1.52% | +0.37% | 56% | +18.0% | -11.6% | 9 |
| Dec | -1.87% | -2.23% | 30% | +10.6% | -9.8% | 10 |
Monthly returns heat map — BIIB
price return, %| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026 | 2.2 | 6.6 | -4.4 | 3.2 | 3.5 | 10.2 | -6.1 | 6.8 | 4.3 | 12.3 | -2.1 | +41.1% | |
| 2025 | -5.9 | -2.4 | -2.6 | -11.5 | 7.2 | -3.2 | 1.9 | 3.3 | 5.9 | 10.1 | 18.0 | -3.4 | +15.1% |
| 2024 | -4.7 | -12.0 | -0.6 | -0.4 | 4.7 | 3.1 | -8.0 | -4.0 | -5.3 | -10.2 | -7.7 | -4.8 | -40.9% |
| 2023 | 5.0 | -7.2 | 3.0 | 9.4 | -2.6 | -3.9 | -5.2 | -1.1 | -3.9 | -7.6 | -1.5 | 10.6 | -6.5% |
| 2022 | -5.8 | -6.6 | -0.2 | -1.5 | -3.6 | 2.0 | 5.5 | -9.2 | 36.7 | 6.2 | 7.7 | -9.3 | +15.4% |
| 2021 | 15.4 | -3.4 | 2.5 | -4.4 | 0.1 | 29.5 | -5.6 | 3.7 | -16.5 | -5.8 | -11.6 | 1.8 | -2.0% |
| 2020 | -9.4 | 14.7 | 2.6 | -6.2 | 3.5 | -12.9 | 2.7 | 4.7 | -1.4 | -11.1 | -4.7 | 1.9 | -17.5% |
| 2019 | 10.9 | -1.7 | -27.9 | -3.0 | -4.3 | 6.7 | 1.7 | -7.6 | 6.0 | 28.3 | 0.4 | -1.0 | -1.4% |
| 2018 | 9.2 | -16.9 | -5.2 | -0.1 | 7.4 | -1.3 | 15.2 | 5.7 | -0.1 | -13.9 | 9.7 | -9.8 | -5.5% |
| 2017 | -2.2 | 4.1 | -5.3 | -0.8 | -8.6 | 9.5 | 6.7 | 9.3 | -1.1 | -0.5 | 3.4 | -1.1 | +12.3% |
| 2016 | -3.6 |