CWT vs SPY: Correlation
Measured on weekly returns over the past three years, California Water Service Group (CWT) and SPDR S&P 500 ETF Trust (SPY) carry a correlation of 0.07, a near-zero link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are CWT and SPY?
Over the past 3 years, CWT and SPY moved with a correlation of 0.07, which is near zero, meaning they move largely independently. The link has loosened recently: the 1-year correlation (-0.18) runs below the 3-year figure (0.07). Over 5 years the correlation is 0.25, and the annualized covariance of weekly returns is 21.4 %².
Within CWT's tracked universe of 15 assets, SPY comes in at #10 by 3-year correlation. The trailing year gives SPY the advantage: +9.3% versus +20.6%, a 11.3-point spread. Note the risk asymmetry: CWT runs 1.5 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.
CWT vs SPY: side by side
| CWT (California Water Service Group) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | +9.3% | +20.6% |
| 5-year return | -12.2% | +82.4% |
| Volatility (ann.) | 22.3% | 14.5% |
| Beta vs S&P 500 | 0.10 | 1.00 |
| Max drawdown (3Y) | -24.1% | -18.8% |
| Market cap | $3.1B | – |
| P/E (trailing) | 22.6 | – |
| Dividend yield | 2.53% | 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 | CWT | SPY |
|---|---|---|
| 2022 | -14.1% | -18.2% |
| 2023 | -12.8% | +26.2% |
| 2024 | -10.6% | +24.9% |
| 2025 | -1.8% | +17.7% |
| 2026 | +18.2% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are CWT and SPY good diversifiers for each other?
By historical standards, yes. A correlation of 0.07 means the two rarely move for the same reasons.
FAQ
What is the correlation between CWT and SPY?
As of 2026-08-27, the correlation of weekly returns between CWT and SPY is 0.07 over 3 years, -0.18 over 1 year and 0.25 over 5 years.
Is SPY a good diversifier for CWT?
By historical standards, yes. A correlation of 0.07 means the two rarely move for the same reasons.
What does a correlation of 0.07 mean?
A reading of 0.07 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: CWT correlations · SPY correlations
