CMS vs SPY: Correlation
How closely do CMS Energy (CMS) and SPDR S&P 500 ETF Trust (SPY) trade together? Their weekly returns over three years give a correlation of -0.01, which is near-zero.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are CMS and SPY?
Over the past 3 years, CMS and SPY moved with a correlation of -0.01, which is near zero, meaning they move largely independently. The link has loosened recently: the 1-year correlation (-0.16) runs below the 3-year figure (-0.01). Over 5 years the correlation is 0.25, and the annualized covariance of weekly returns is -1.8 %².
Among the 42 assets we track against CMS, SPY ranks #30 by 3-year correlation. Correlation aside, the last 12 months split them widely, with SPY ahead by 23.0 points (-2.4% versus +20.6%). Do not treat this figure as fixed: across three years the rolling one-year correlation ranged all the way from -0.21 to 0.41.
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.
CMS vs SPY: side by side
| CMS (CMS Energy) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | -2.4% | +20.6% |
| 5-year return | +23.8% | +82.4% |
| Volatility (ann.) | 16.2% | 14.5% |
| Beta vs S&P 500 | -0.01 | 1.00 |
| Max drawdown (3Y) | -13.2% | -18.8% |
| Market cap | $21.4B | – |
| P/E (trailing) | 20.8 | – |
| Dividend yield | 3.21% | 1.01% |
| Expense ratio | – | 0.09% |
| Assets under management | – | $795.3B |
| Sector / category | Utilities | 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 | CMS | SPY |
|---|---|---|
| 2022 | +0.2% | -18.2% |
| 2023 | -5.2% | +26.2% |
| 2024 | +18.6% | +24.9% |
| 2025 | +8.1% | +17.7% |
| 2026 | +0.0% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are CMS and SPY good diversifiers for each other?
Yes: at -0.01, the two have gone their own ways historically, which is what genuine diversification looks like.
FAQ
What is the correlation between CMS and SPY?
Using weekly returns as of 2026-08-27: -0.01 over 3 years, with -0.16 over the last year and 0.25 over 5 years.
Is SPY a good diversifier for CMS?
Yes: at -0.01, the two have gone their own ways historically, which is what genuine diversification looks like.
What does a correlation of -0.01 mean?
On the −1 to +1 scale, -0.01 describes how much the two returns move together: +1 is lockstep, 0 is independence, negative values mean opposite directions. It says nothing about which performed better.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/cms-vs-spy.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/cms-vs-spy/)
Free with attribution; caching and terms are described in the API documentation.
Related comparisons
Hubs: CMS correlations · SPY correlations
