CERS vs SPY: Correlation
Measured on weekly returns over the past three years, Cerus Corporation (CERS) and SPDR S&P 500 ETF Trust (SPY) carry a correlation of 0.41, a moderate link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are CERS and SPY?
On 3 years of weekly data the CERS/SPY correlation comes out at 0.41, moderate. The link has loosened recently: the 1-year correlation (0.20) runs below the 3-year figure (0.41). The 5-year figure is 0.43, and annualized covariance runs at 420.0 %².
Among the 10 assets we track against CERS, SPY sits near the bottom by co-movement, at rank #6. The last year tells two different stories: CERS led by 87.0 percentage points, +107.6% for CERS against +20.6% for SPY. Note the risk asymmetry: CERS runs 4.9 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.
CERS vs SPY: side by side
| CERS (Cerus Corporation) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | +107.6% | +20.6% |
| 5-year return | -57.3% | +82.4% |
| Volatility (ann.) | 71.0% | 14.5% |
| Beta vs S&P 500 | 2.01 | 1.00 |
| Max drawdown (3Y) | -52.1% | -18.8% |
| Market cap | $0.5B | – |
| P/E (trailing) | – | – |
| 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 | CERS | SPY |
|---|---|---|
| 2022 | -46.4% | -18.2% |
| 2023 | -40.8% | +26.2% |
| 2024 | -28.7% | +24.9% |
| 2025 | +33.8% | +17.7% |
| 2026 | +32.0% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are CERS and SPY good diversifiers for each other?
Yes, to a useful degree: a correlation of 0.41 leaves real independence between the two, which historically damped combined volatility.
FAQ
What is the correlation between CERS and SPY?
As of 2026-08-27, the correlation of weekly returns between CERS and SPY is 0.41 over 3 years, 0.20 over 1 year and 0.43 over 5 years.
Is SPY a good diversifier for CERS?
Yes, to a useful degree: a correlation of 0.41 leaves real independence between the two, which historically damped combined volatility.
What does a correlation of 0.41 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: CERS correlations · SPY correlations
