BIIB vs LLY: Correlation
Measured on weekly returns over the past three years, Biogen (BIIB) and Lilly (Eli) (LLY) carry a correlation of 0.36, a moderate link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are BIIB and LLY?
Over the past 3 years, BIIB and LLY moved with a correlation of 0.36, which is moderate. The link has tightened recently: the 1-year correlation (0.47) runs above the 3-year figure (0.36). Over 5 years the correlation is 0.35, and the annualized covariance of weekly returns is 400.6 %².
Among the 32 assets we track against BIIB, LLY ranks #19 by 3-year correlation. Twelve-month performance is nearly a tie, at +62.4% for BIIB and +61.2% for LLY. The relationship is regime-dependent: the rolling one-year correlation swung between -0.07 and 0.58 over the past three years, so this pair behaves very differently depending on the market environment.
How is this computed?
Pearson correlation on weekly returns: ρ(A,B) = cov(rA, rB) / (σA · σB), over windows of 52, 156 and 260 weeks. Covariance is annualized (×52) and expressed in %². Full definitions on the methodology page.
BIIB vs LLY: side by side
| BIIB (Biogen) | LLY (Lilly (Eli)) | |
|---|---|---|
| 1-year return | +62.4% | +61.2% |
| 5-year return | -35.7% | +369.2% |
| Volatility (ann.) | 30.1% | 36.6% |
| Beta vs S&P 500 | 0.53 | 0.57 |
| Max drawdown (3Y) | -57.7% | -34.5% |
| Market cap | $32.7B | $1,048.8B |
| P/E (trailing) | 39.2 | 40.0 |
| Dividend yield | 0.00% | 0.54% |
| Sector / category | Health Care | Health Care |
Year-by-year returns
| Year | BIIB | LLY |
|---|---|---|
| 2022 | +15.4% | +34.3% |
| 2023 | -6.6% | +60.9% |
| 2024 | -40.9% | +33.3% |
| 2025 | +15.1% | +40.2% |
| 2026 | +25.9% | +10.0% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are BIIB and LLY good diversifiers for each other?
A fair diversifier. At 0.36, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
FAQ
What is the correlation between BIIB and LLY?
The BIIB/LLY correlation stands at 0.36 on a 3-year window (1 year: 0.47, 5 years: 0.35), computed from weekly returns as of 2026-08-27.
Is LLY a good diversifier for BIIB?
A fair diversifier. At 0.36, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
What does a correlation of 0.36 mean?
A reading of 0.36 sits on a scale from −1 (opposite moves) through 0 (unrelated) to +1 (identical moves). Correlation captures direction, not magnitude or performance.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/biib-vs-lly.json
Markdown for the live badge, attribution link included:
[](https://www.pairbook.io/pair/biib-vs-lly/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: BIIB correlations · LLY correlations
