CSTL vs GH: Correlation
Measured on weekly returns over the past three years, Castle Biosciences, Inc. (CSTL) and Guardant Health, Inc. (GH) carry a correlation of 0.50, a moderate link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are CSTL and GH?
Over the past 3 years, CSTL and GH moved with a correlation of 0.50, which is moderate. Recent behaviour matches the longer record: 0.47 over 1 year against 0.50 over 3. Over 5 years the correlation is 0.45, and the annualized covariance of weekly returns is 2070.0 %².
In CSTL's tracked universe of 12 assets, GH sits right near the top at #1. Correlation aside, the last 12 months split them widely, with GH ahead by 111.6 points (+53.8% versus +165.4%).
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.
CSTL vs GH: side by side
| CSTL (Castle Biosciences, Inc.) | GH (Guardant Health, Inc.) | |
|---|---|---|
| 1-year return | +53.8% | +165.4% |
| 5-year return | -54.0% | +33.5% |
| Volatility (ann.) | 64.2% | 64.9% |
| Beta vs S&P 500 | 0.79 | 1.44 |
| Max drawdown (3Y) | -57.8% | -59.8% |
| Market cap | $1.0B | $22.6B |
| P/E (trailing) | – | – |
| Dividend yield | 0.00% | 0.00% |
| Sector / category | US Listed | US Listed |
Year-by-year returns
| Year | CSTL | GH |
|---|---|---|
| 2022 | -45.1% | -72.8% |
| 2023 | -8.3% | -0.6% |
| 2024 | +23.5% | +12.9% |
| 2025 | +46.0% | +234.3% |
| 2026 | -11.9% | +65.0% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are CSTL and GH good diversifiers for each other?
Only partially. A correlation of 0.50 means CSTL and GH share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
FAQ
What is the correlation between CSTL and GH?
As of 2026-08-27, the correlation of weekly returns between CSTL and GH is 0.50 over 3 years, 0.47 over 1 year and 0.45 over 5 years.
Is GH a good diversifier for CSTL?
Only partially. A correlation of 0.50 means CSTL and GH share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
What does a correlation of 0.50 mean?
On the −1 to +1 scale, 0.50 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/cstl-vs-gh.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/cstl-vs-gh/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: CSTL correlations · GH correlations
