RLYB vs SPY: Correlation
How closely do Rallybio Corporation (RLYB) and SPDR S&P 500 ETF Trust (SPY) trade together? Their weekly returns over three years give a correlation of 0.11, which is weak.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are RLYB and SPY?
Over the past 3 years, RLYB and SPY moved with a correlation of 0.11, which is weak. The relationship has been stable: the 1-year correlation (0.05) sits close to the 3-year figure. Over 5 years the correlation is 0.10, and the annualized covariance of weekly returns is 163.3 %².
Out of 11 assets tracked against RLYB, SPY lands near the bottom at #7. The last year tells two different stories: RLYB led by 234.5 percentage points, +255.1% for RLYB against +20.6% for SPY. One caveat on sizing: RLYB is 6.8 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.
RLYB vs SPY: side by side
| RLYB (Rallybio Corporation) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | +255.1% | +20.6% |
| 5-year return | -83.7% | +82.4% |
| Volatility (ann.) | 99.0% | 14.5% |
| Beta vs S&P 500 | 0.78 | 1.00 |
| Max drawdown (3Y) | -95.5% | -18.8% |
| Market cap | $0.1B | – |
| P/E (trailing) | 2.1 | – |
| Dividend yield | 0.00% | 1.01% |
| Expense ratio | – | 0.09% |
| Assets under management | – | $795.3B |
| Sector / category | US Listed | ETF · US Large Cap |
SPY is a Large Blend fund from State Street Investment Management: $795.3B under management, 504 holdings, a 0.09% expense ratio, a 1.01% trailing dividend yield.
Year-by-year returns
| Year | RLYB | SPY |
|---|---|---|
| 2022 | -31.1% | -18.2% |
| 2023 | -63.6% | +26.2% |
| 2024 | -59.8% | +24.9% |
| 2025 | -28.5% | +17.7% |
| 2026 | +205.4% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are RLYB and SPY good diversifiers for each other?
By historical standards, yes. A correlation of 0.11 means the two rarely move for the same reasons.
FAQ
What is the correlation between RLYB and SPY?
Using weekly returns as of 2026-08-27: 0.11 over 3 years, with 0.05 over the last year and 0.10 over 5 years.
Is SPY a good diversifier for RLYB?
By historical standards, yes. A correlation of 0.11 means the two rarely move for the same reasons.
What does a correlation of 0.11 mean?
A reading of 0.11 sits on a scale from −1 (opposite moves) through 0 (unrelated) to +1 (identical moves). Correlation captures direction, not magnitude or performance.
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Related comparisons
Hubs: RLYB correlations · SPY correlations
