SPRO vs SPY: Correlation
Spero Therapeutics, Inc. (SPRO) and SPDR S&P 500 ETF Trust (SPY) show a weak relationship: their 3-year correlation of weekly returns is 0.15.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are SPRO and SPY?
On 3 years of weekly data the SPRO/SPY correlation comes out at 0.15, weak. Recent behaviour matches the longer record: 0.18 over 1 year against 0.15 over 3. The 5-year figure is 0.12, and annualized covariance runs at 337.3 %².
Among the 18 assets we track against SPRO, SPY ranks #12 by 3-year correlation. The last year tells two different stories: SPY led by 59.5 percentage points, -38.9% for SPRO against +20.6% for SPY. Note the risk asymmetry: SPRO runs 11.0 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.
SPRO vs SPY: side by side
| SPRO (Spero Therapeutics, Inc.) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | -38.9% | +20.6% |
| 5-year return | -93.3% | +82.4% |
| Volatility (ann.) | 159.8% | 14.5% |
| Beta vs S&P 500 | 1.61 | 1.00 |
| Max drawdown (3Y) | -68.9% | -18.8% |
| Market cap | $0.1B | – |
| P/E (trailing) | 8.6 | – |
| 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 | SPRO | SPY |
|---|---|---|
| 2022 | -89.2% | -18.2% |
| 2023 | -15.0% | +26.2% |
| 2024 | -29.9% | +24.9% |
| 2025 | +126.2% | +17.7% |
| 2026 | -48.1% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are SPRO and SPY good diversifiers for each other?
By historical standards, yes. A correlation of 0.15 means the two rarely move for the same reasons.
FAQ
What is the correlation between SPRO and SPY?
Using weekly returns as of 2026-08-27: 0.15 over 3 years, with 0.18 over the last year and 0.12 over 5 years.
Is SPY a good diversifier for SPRO?
By historical standards, yes. A correlation of 0.15 means the two rarely move for the same reasons.
What does a correlation of 0.15 mean?
A reading of 0.15 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: SPRO correlations · SPY correlations
