WAT vs WST: Correlation
Waters Corporation (WAT) and West Pharmaceutical Services (WST) show a moderate relationship: their 3-year correlation of weekly returns is 0.39.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are WAT and WST?
Across a 3-year window, the weekly returns of WAT and WST correlate at 0.39, moderate. Recent behaviour matches the longer record: 0.32 over 1 year against 0.39 over 3. Stretching to 5 years gives 0.45, with an annualized covariance of 527.6 %².
Among the 33 assets we track against WAT, WST ranks #20 by 3-year correlation. Twelve-month performance is nearly a tie, at +43.0% for WAT and +41.1% for WST. On a rolling one-year basis the correlation drifted between 0.18 and 0.58, 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.
WAT vs WST: side by side
| WAT (Waters Corporation) | WST (West Pharmaceutical Services) | |
|---|---|---|
| 1-year return | +43.0% | +41.1% |
| 5-year return | +2.0% | -22.4% |
| Volatility (ann.) | 35.3% | 38.6% |
| Beta vs S&P 500 | 0.89 | 0.86 |
| Max drawdown (3Y) | -33.4% | -53.8% |
| Market cap | $41.4B | $24.4B |
| P/E (trailing) | 105.3 | 44.8 |
| Dividend yield | 0.00% | 0.25% |
| Sector / category | Health Care | Health Care |
Year-by-year returns
| Year | WAT | WST |
|---|---|---|
| 2022 | -8.1% | -49.7% |
| 2023 | -3.9% | +50.0% |
| 2024 | +12.7% | -6.8% |
| 2025 | +2.4% | -15.7% |
| 2026 | +10.9% | +26.1% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are WAT and WST good diversifiers for each other?
Reasonably. At 0.39, WAT and WST keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
FAQ
What is the correlation between WAT and WST?
As of 2026-08-27, the correlation of weekly returns between WAT and WST is 0.39 over 3 years, 0.32 over 1 year and 0.45 over 5 years.
Is WST a good diversifier for WAT?
Reasonably. At 0.39, WAT and WST keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
What does a correlation of 0.39 mean?
A reading of 0.39 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/wat-vs-wst.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/wat-vs-wst/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: WAT correlations · WST correlations
