CSTL vs VXX: Correlation
Castle Biosciences, Inc. (CSTL) and iPath Series B S&P 500 VIX Short-Term Futures ETN (VXX) show a negative relationship: their 3-year correlation of weekly returns is -0.21.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are CSTL and VXX?
Across a 3-year window, the weekly returns of CSTL and VXX correlate at -0.21, negative, meaning they tend to move in opposite directions. The link has tightened recently: the 1-year correlation (-0.09) runs above the 3-year figure (-0.21). Stretching to 5 years gives -0.18, with an annualized covariance of -830.6 %².
Among the 12 assets we track against CSTL, VXX sits near the bottom by co-movement, at rank #11. Correlation aside, the last 12 months split them widely, with CSTL ahead by 103.5 points (+53.8% versus -49.7%).
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 VXX: side by side
| CSTL (Castle Biosciences, Inc.) | VXX (iPath Series B S&P 500 VIX Short-Term Futures ETN) | |
|---|---|---|
| 1-year return | +53.8% | -49.7% |
| 5-year return | -54.0% | -95.6% |
| Volatility (ann.) | 64.2% | 60.9% |
| Beta vs S&P 500 | 0.79 | -3.31 |
| Max drawdown (3Y) | -57.8% | -83.3% |
| Market cap | $1.0B | – |
| P/E (trailing) | – | – |
| Dividend yield | 0.00% | 0.00% |
| Sector / category | US Listed | US Listed |
Year-by-year returns
| Year | CSTL | VXX |
|---|---|---|
| 2022 | -45.1% | -23.8% |
| 2023 | -8.3% | -72.5% |
| 2024 | +23.5% | -26.2% |
| 2025 | +46.0% | -42.2% |
| 2026 | -11.9% | -31.6% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are CSTL and VXX good diversifiers for each other?
By historical standards, yes. A correlation of -0.21 means the two rarely move for the same reasons.
FAQ
What is the correlation between CSTL and VXX?
As of 2026-08-27, the correlation of weekly returns between CSTL and VXX is -0.21 over 3 years, -0.09 over 1 year and -0.18 over 5 years.
Is VXX a good diversifier for CSTL?
By historical standards, yes. A correlation of -0.21 means the two rarely move for the same reasons.
What does a correlation of -0.21 mean?
A reading of -0.21 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/cstl-vs-vxx.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/cstl-vs-vxx/)
Free with attribution; caching and terms are described in the API documentation.
Related comparisons
Hubs: CSTL correlations · VXX correlations
