BOLD vs XBI: Correlation
Boundless Bio, Inc. (BOLD) and SPDR S&P Biotech ETF (XBI) show a moderate relationship: their 3-year correlation of weekly returns is 0.46.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are BOLD and XBI?
Across a 3-year window, the weekly returns of BOLD and XBI correlate at 0.46, moderate. Recent behaviour matches the longer record: 0.52 over 1 year against 0.46 over 3. Stretching to 5 years gives n/a, with an annualized covariance of 1113.1 %².
Among the 18 assets we track against BOLD, XBI ranks #4 by 3-year correlation. Correlation aside, the last 12 months split them widely, with BOLD ahead by 63.7 points (+150.9% versus +87.2%). Note the risk asymmetry: BOLD runs 3.3 times the annualized volatility of the other leg, so equal-weighting the two is not an equal-risk position.
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.
BOLD vs XBI: side by side
| BOLD (Boundless Bio, Inc.) | XBI (SPDR S&P Biotech ETF) | |
|---|---|---|
| 1-year return | +150.9% | +87.2% |
| 5-year return | n/a | +28.6% |
| Volatility (ann.) | 90.9% | 27.7% |
| Beta vs S&P 500 | 1.60 | 1.09 |
| Max drawdown (3Y) | -92.9% | -33.0% |
| Market cap | $0.1B | – |
| P/E (trailing) | – | – |
| Dividend yield | 0.00% | – |
| Sector / category | US Listed | ETF · Thematic |
Year-by-year returns
| Year | BOLD | XBI |
|---|---|---|
| 2022 | – | -25.9% |
| 2023 | – | +7.6% |
| 2024 | – | +1.0% |
| 2025 | -58.6% | +35.9% |
| 2026 | +138.3% | +38.1% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are BOLD and XBI good diversifiers for each other?
Reasonably. At 0.46, BOLD and XBI keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
FAQ
What is the correlation between BOLD and XBI?
As of 2026-08-27, the correlation of weekly returns between BOLD and XBI is 0.46 over 3 years, 0.52 over 1 year and n/a over 5 years.
Is XBI a good diversifier for BOLD?
Reasonably. At 0.46, BOLD and XBI keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
What does a correlation of 0.46 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.
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Related comparisons
Hubs: BOLD correlations · XBI correlations
