AMPH vs SPY: Correlation
How closely do Amphastar Pharmaceuticals, Inc. (AMPH) and SPDR S&P 500 ETF Trust (SPY) trade together? Their weekly returns over three years give a correlation of 0.22, which is weak.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are AMPH and SPY?
Over the past 3 years, AMPH and SPY moved with a correlation of 0.22, which is weak. The relationship has been stable: the 1-year correlation (0.16) sits close to the 3-year figure. Over 5 years the correlation is 0.20, and the annualized covariance of weekly returns is 140.3 %².
Within AMPH's tracked universe of 13 assets, SPY comes in at #8 by 3-year correlation. Correlation aside, the last 12 months split them widely, with SPY ahead by 48.8 points (-28.2% versus +20.6%). Risk is not evenly split, since AMPH carries 3.0 times the volatility of the other side.
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 SPY: side by side
| AMPH (Amphastar Pharmaceuticals, Inc.) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | -28.2% | +20.6% |
| 5-year return | +12.9% | +82.4% |
| Volatility (ann.) | 44.1% | 14.5% |
| Beta vs S&P 500 | 0.67 | 1.00 |
| Max drawdown (3Y) | -73.4% | -18.8% |
| Market cap | $0.9B | – |
| P/E (trailing) | 13.0 | – |
| Dividend yield | 0.00% | 1.01% |
| Expense ratio | – | 0.09% |
| Assets under management | – | $795.3B |
| Sector / category | US Listed | ETF · US Large Cap |
SPY is a Large Blend fund from State Street Investment Management: $795.3B under management, 504 holdings, a 0.09% expense ratio, a 1.01% trailing dividend yield.
Year-by-year returns
| Year | AMPH | SPY |
|---|---|---|
| 2022 | +20.3% | -18.2% |
| 2023 | +120.7% | +26.2% |
| 2024 | -40.0% | +24.9% |
| 2025 | -27.9% | +17.7% |
| 2026 | -18.3% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are AMPH and SPY good diversifiers for each other?
Yes, to a useful degree: a correlation of 0.22 leaves real independence between the two, which historically damped combined volatility.
FAQ
What is the correlation between AMPH and SPY?
The AMPH/SPY correlation stands at 0.22 on a 3-year window (1 year: 0.16, 5 years: 0.20), computed from weekly returns as of 2026-08-27.
Is SPY a good diversifier for AMPH?
Yes, to a useful degree: a correlation of 0.22 leaves real independence between the two, which historically damped combined volatility.
What does a correlation of 0.22 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/amph-vs-spy.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/amph-vs-spy/)
Free with attribution; caching and terms are described in the API documentation.
Related comparisons
Hubs: AMPH correlations · SPY correlations
