HSTM vs SPY: Correlation
HealthStream, Inc. (HSTM) and SPDR S&P 500 ETF Trust (SPY) show a weak relationship: their 3-year correlation of weekly returns is 0.28.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are HSTM and SPY?
Over the past 3 years, HSTM and SPY moved with a correlation of 0.28, which is weak. The past 12 months show a weaker link (0.17) than the 3-year average (0.28). Over 5 years the correlation is 0.35, and the annualized covariance of weekly returns is 112.0 %².
Within HSTM's tracked universe of 13 assets, SPY comes in at #8 by 3-year correlation. The last year tells two different stories: SPY led by 18.4 percentage points, +2.2% for HSTM against +20.6% for SPY. Risk is not evenly split, since HSTM carries 1.9 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.
HSTM vs SPY: side by side
| HSTM (HealthStream, Inc.) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | +2.2% | +20.6% |
| 5-year return | -1.6% | +82.4% |
| Volatility (ann.) | 27.4% | 14.5% |
| Beta vs S&P 500 | 0.54 | 1.00 |
| Max drawdown (3Y) | -41.4% | -18.8% |
| Market cap | $0.8B | – |
| P/E (trailing) | 40.0 | – |
| Dividend yield | 0.46% | 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 | HSTM | SPY |
|---|---|---|
| 2022 | -5.8% | -18.2% |
| 2023 | +9.3% | +26.2% |
| 2024 | +18.1% | +24.9% |
| 2025 | -27.1% | +17.7% |
| 2026 | +25.5% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are HSTM and SPY good diversifiers for each other?
Reasonably. At 0.28, HSTM and SPY keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
FAQ
What is the correlation between HSTM and SPY?
The HSTM/SPY correlation stands at 0.28 on a 3-year window (1 year: 0.17, 5 years: 0.35), computed from weekly returns as of 2026-08-27.
Is SPY a good diversifier for HSTM?
Reasonably. At 0.28, HSTM and SPY keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
What does a correlation of 0.28 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/hstm-vs-spy.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/hstm-vs-spy/)
Free with attribution; caching and terms are described in the API documentation.
Related comparisons
Hubs: HSTM correlations · SPY correlations
