BIIB vs XBI: Correlation
How closely do Biogen (BIIB) and SPDR S&P Biotech ETF (XBI) trade together? Their weekly returns over three years give a correlation of 0.48, which is moderate.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are BIIB and XBI?
On 3 years of weekly data the BIIB/XBI correlation comes out at 0.48, moderate. The past 12 months show a weaker link (0.33) than the 3-year average (0.48). The 5-year figure is 0.45, and annualized covariance runs at 395.8 %².
Among the 32 assets we track against BIIB, XBI ranks #8 by 3-year correlation. The last year tells two different stories: XBI led by 24.8 percentage points, +62.4% for BIIB against +87.2% for XBI. On a rolling one-year basis the correlation drifted between 0.34 and 0.64, a moderate band.
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 XBI: side by side
| BIIB (Biogen) | XBI (SPDR S&P Biotech ETF) | |
|---|---|---|
| 1-year return | +62.4% | +87.2% |
| 5-year return | -35.7% | +28.6% |
| Volatility (ann.) | 30.1% | 27.7% |
| Beta vs S&P 500 | 0.53 | 1.09 |
| Max drawdown (3Y) | -57.7% | -33.0% |
| Market cap | $32.7B | – |
| P/E (trailing) | 39.2 | – |
| Dividend yield | 0.00% | – |
| Sector / category | Health Care | ETF · Thematic |
Year-by-year returns
| Year | BIIB | XBI |
|---|---|---|
| 2022 | +15.4% | -25.9% |
| 2023 | -6.6% | +7.6% |
| 2024 | -40.9% | +1.0% |
| 2025 | +15.1% | +35.9% |
| 2026 | +25.9% | +38.1% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are BIIB and XBI good diversifiers for each other?
A fair diversifier. At 0.48, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
FAQ
What is the correlation between BIIB and XBI?
The BIIB/XBI correlation stands at 0.48 on a 3-year window (1 year: 0.33, 5 years: 0.45), computed from weekly returns as of 2026-08-27.
Is XBI a good diversifier for BIIB?
A fair diversifier. At 0.48, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
What does a correlation of 0.48 mean?
On the −1 to +1 scale, 0.48 describes how much the two returns move together: +1 is lockstep, 0 is independence, negative values mean opposite directions. It says nothing about which performed better.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/biib-vs-xbi.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/biib-vs-xbi/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: BIIB correlations · XBI correlations
