ICU vs SPY: Correlation
SeaStar Medical Holding Corporation (ICU) and SPDR S&P 500 ETF Trust (SPY) show a near-zero relationship: their 3-year correlation of weekly returns is 0.08.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are ICU and SPY?
Across a 3-year window, the weekly returns of ICU and SPY correlate at 0.08, near zero, meaning they move largely independently. Lately the two have moved closer together, with the 1-year correlation at 0.38 versus 0.08 over 3 years. Stretching to 5 years gives 0.10, with an annualized covariance of 172.1 %².
SPY is close to the least connected end of ICU's tracked universe, ranking #6 of 10. The last year tells two different stories: SPY led by 84.0 percentage points, -63.4% for ICU against +20.6% for SPY. One caveat on sizing: ICU is 10.8 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.
ICU vs SPY: side by side
| ICU (SeaStar Medical Holding Corporation) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | -63.4% | +20.6% |
| 5-year return | -99.9% | +82.4% |
| Volatility (ann.) | 156.9% | 14.5% |
| Beta vs S&P 500 | 0.82 | 1.00 |
| Max drawdown (3Y) | -99.4% | -18.8% |
| Market cap | – | – |
| 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 | ICU | SPY |
|---|---|---|
| 2022 | -59.2% | -18.2% |
| 2023 | -89.2% | +26.2% |
| 2024 | -82.5% | +24.9% |
| 2025 | -87.6% | +17.7% |
| 2026 | +29.2% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are ICU and SPY good diversifiers for each other?
Yes. With a correlation of 0.08, ICU and SPY have moved largely independently, which makes them a genuinely diversifying pair by historical standards.
FAQ
What is the correlation between ICU and SPY?
As of 2026-08-27, the correlation of weekly returns between ICU and SPY is 0.08 over 3 years, 0.38 over 1 year and 0.10 over 5 years.
Is SPY a good diversifier for ICU?
Yes. With a correlation of 0.08, ICU and SPY have moved largely independently, which makes them a genuinely diversifying pair by historical standards.
What does a correlation of 0.08 mean?
A reading of 0.08 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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