SNDX vs XBI: Correlation
How closely do Syndax Pharmaceuticals, Inc. (SNDX) and SPDR S&P Biotech ETF (XBI) trade together? Their weekly returns over three years give a correlation of 0.65, which is strong.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are SNDX and XBI?
Over the past 3 years, SNDX and XBI moved with a correlation of 0.65, which is strong. The past 12 months show a weaker link (0.52) than the 3-year average (0.65). Over 5 years the correlation is 0.60, and the annualized covariance of weekly returns is 1038.6 %².
Few assets follow SNDX as closely as XBI, which ranks #1 of 18 tracked partners. Correlation aside, the last 12 months split them widely, with XBI ahead by 63.2 points (+24.0% versus +87.2%). One caveat on sizing: SNDX is 2.1 times as volatile as the other leg, so an equal-dollar split is far from equal-risk.
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.
SNDX vs XBI: side by side
| SNDX (Syndax Pharmaceuticals, Inc.) | XBI (SPDR S&P Biotech ETF) | |
|---|---|---|
| 1-year return | +24.0% | +87.2% |
| 5-year return | +16.9% | +28.6% |
| Volatility (ann.) | 57.8% | 27.7% |
| Beta vs S&P 500 | 1.25 | 1.09 |
| Max drawdown (3Y) | -64.8% | -33.0% |
| Market cap | $1.8B | – |
| P/E (trailing) | – | – |
| Dividend yield | 0.00% | – |
| Sector / category | US Listed | ETF · Thematic |
Year-by-year returns
| Year | SNDX | XBI |
|---|---|---|
| 2022 | +16.3% | -25.9% |
| 2023 | -15.1% | +7.6% |
| 2024 | -38.8% | +1.0% |
| 2025 | +58.9% | +35.9% |
| 2026 | -4.0% | +38.1% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are SNDX and XBI good diversifiers for each other?
Somewhat, no more. With 0.65 correlation, most large moves hit both names, and the diversification benefit stays modest.
FAQ
What is the correlation between SNDX and XBI?
The SNDX/XBI correlation stands at 0.65 on a 3-year window (1 year: 0.52, 5 years: 0.60), computed from weekly returns as of 2026-08-27.
Is XBI a good diversifier for SNDX?
Somewhat, no more. With 0.65 correlation, most large moves hit both names, and the diversification benefit stays modest.
What does a correlation of 0.65 mean?
A reading of 0.65 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/sndx-vs-xbi.json
Embed this badge (it refreshes with the data), with attribution:
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Related comparisons
Hubs: SNDX correlations · XBI correlations
