AMPH vs ZTS: Correlation
Amphastar Pharmaceuticals, Inc. (AMPH) and Zoetis (ZTS) show a moderate relationship: their 3-year correlation of weekly returns is 0.43.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are AMPH and ZTS?
On 3 years of weekly data the AMPH/ZTS correlation comes out at 0.43, moderate. The relationship has been stable: the 1-year correlation (0.45) sits close to the 3-year figure. The 5-year figure is 0.30, and annualized covariance runs at 567.1 %².
Within AMPH's tracked universe of 13 assets, ZTS comes in at #6 by 3-year correlation. Correlation aside, the last 12 months split them widely, with AMPH ahead by 22.6 points (-28.2% versus -50.8%).
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.
AMPH vs ZTS: side by side
| AMPH (Amphastar Pharmaceuticals, Inc.) | ZTS (Zoetis) | |
|---|---|---|
| 1-year return | -28.2% | -50.8% |
| 5-year return | +12.9% | -61.5% |
| Volatility (ann.) | 44.1% | 30.1% |
| Beta vs S&P 500 | 0.67 | 0.51 |
| Max drawdown (3Y) | -73.4% | -63.0% |
| Market cap | $0.9B | $31.0B |
| P/E (trailing) | 13.0 | 12.7 |
| Dividend yield | 0.00% | 2.66% |
| Sector / category | US Listed | Health Care |
Year-by-year returns
| Year | AMPH | ZTS |
|---|---|---|
| 2022 | +20.3% | -39.5% |
| 2023 | +120.7% | +35.9% |
| 2024 | -40.0% | -16.6% |
| 2025 | -27.9% | -21.8% |
| 2026 | -18.3% | -39.4% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are AMPH and ZTS good diversifiers for each other?
Yes, to a useful degree: a correlation of 0.43 leaves real independence between the two, which historically damped combined volatility.
FAQ
What is the correlation between AMPH and ZTS?
Using weekly returns as of 2026-08-27: 0.43 over 3 years, with 0.45 over the last year and 0.30 over 5 years.
Is ZTS a good diversifier for AMPH?
Yes, to a useful degree: a correlation of 0.43 leaves real independence between the two, which historically damped combined volatility.
What does a correlation of 0.43 mean?
On the −1 to +1 scale, 0.43 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/amph-vs-zts.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/amph-vs-zts/)
Free with attribution; caching and terms are described in the API documentation.
Related comparisons
Hubs: AMPH correlations · ZTS correlations
