CLDX vs XBI: Correlation
How closely do Celldex Therapeutics, Inc. (CLDX) and SPDR S&P Biotech ETF (XBI) trade together? Their weekly returns over three years give a correlation of 0.66, which is strong.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are CLDX and XBI?
On 3 years of weekly data the CLDX/XBI correlation comes out at 0.66, strong. The link has loosened recently: the 1-year correlation (0.49) runs below the 3-year figure (0.66). The 5-year figure is 0.67, and annualized covariance runs at 1085.5 %².
In CLDX's tracked universe of 18 assets, XBI sits right near the top at #1. On 12-month performance XBI holds a 8.2-point edge, +79.0% against +87.2%. Risk is not evenly split, since CLDX carries 2.1 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.
CLDX vs XBI: side by side
| CLDX (Celldex Therapeutics, Inc.) | XBI (SPDR S&P Biotech ETF) | |
|---|---|---|
| 1-year return | +79.0% | +87.2% |
| 5-year return | -21.9% | +28.6% |
| Volatility (ann.) | 59.4% | 27.7% |
| Beta vs S&P 500 | 1.48 | 1.09 |
| Max drawdown (3Y) | -70.8% | -33.0% |
| Market cap | $3.2B | – |
| P/E (trailing) | – | – |
| Dividend yield | 0.00% | – |
| Sector / category | US Listed | ETF · Thematic |
Year-by-year returns
| Year | CLDX | XBI |
|---|---|---|
| 2022 | +15.3% | -25.9% |
| 2023 | -11.0% | +7.6% |
| 2024 | -36.3% | +1.0% |
| 2025 | +7.5% | +35.9% |
| 2026 | +49.0% | +38.1% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are CLDX and XBI good diversifiers for each other?
Only partially. A correlation of 0.66 means CLDX and XBI 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 CLDX and XBI?
As of 2026-08-27, the correlation of weekly returns between CLDX and XBI is 0.66 over 3 years, 0.49 over 1 year and 0.67 over 5 years.
Is XBI a good diversifier for CLDX?
Only partially. A correlation of 0.66 means CLDX and XBI share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
What does a correlation of 0.66 mean?
On the −1 to +1 scale, 0.66 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/cldx-vs-xbi.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/cldx-vs-xbi/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: CLDX correlations · XBI correlations
