BIO vs WST: Correlation
Measured on weekly returns over the past three years, Bio-Rad Laboratories, Inc. (BIO) and West Pharmaceutical Services (WST) carry a correlation of 0.42, a moderate link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are BIO and WST?
On 3 years of weekly data the BIO/WST correlation comes out at 0.42, moderate. The relationship has been stable: the 1-year correlation (0.39) sits close to the 3-year figure. The 5-year figure is 0.55, and annualized covariance runs at 624.8 %².
Among the 13 assets we track against BIO, WST ranks #7 by 3-year correlation. The trailing year gives WST the advantage: +33.2% versus +41.1%, a 7.9-point spread.
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.
BIO vs WST: side by side
| BIO (Bio-Rad Laboratories, Inc.) | WST (West Pharmaceutical Services) | |
|---|---|---|
| 1-year return | +33.2% | +41.1% |
| 5-year return | -52.1% | -22.4% |
| Volatility (ann.) | 38.4% | 38.6% |
| Beta vs S&P 500 | 0.85 | 0.86 |
| Max drawdown (3Y) | -45.9% | -53.8% |
| Market cap | $10.4B | $24.4B |
| P/E (trailing) | 47.4 | 44.8 |
| Dividend yield | 0.00% | 0.25% |
| Sector / category | US Listed | Health Care |
Year-by-year returns
| Year | BIO | WST |
|---|---|---|
| 2022 | -44.3% | -49.7% |
| 2023 | -23.2% | +50.0% |
| 2024 | +1.7% | -6.8% |
| 2025 | -7.8% | -15.7% |
| 2026 | +28.7% | +26.1% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are BIO and WST good diversifiers for each other?
Reasonably. At 0.42, BIO and WST keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
FAQ
What is the correlation between BIO and WST?
The BIO/WST correlation stands at 0.42 on a 3-year window (1 year: 0.39, 5 years: 0.55), computed from weekly returns as of 2026-08-27.
Is WST a good diversifier for BIO?
Reasonably. At 0.42, BIO and WST keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
What does a correlation of 0.42 mean?
Correlation ranges from −1 to +1. Values near +1 mean two assets move together, near 0 that they move independently, and negative values that they tend to move in opposite directions. It measures co-movement, not performance.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/bio-vs-wst.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/bio-vs-wst/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: BIO correlations · WST correlations
