CMI vs SPY: Correlation
Measured on weekly returns over the past three years, Cummins (CMI) and SPDR S&P 500 ETF Trust (SPY) carry a correlation of 0.59, a moderate link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are CMI and SPY?
Over the past 3 years, CMI and SPY moved with a correlation of 0.59, which is moderate. The link has loosened recently: the 1-year correlation (0.41) runs below the 3-year figure (0.59). Over 5 years the correlation is 0.61, and the annualized covariance of weekly returns is 219.8 %².
Within CMI's tracked universe of 36 assets, SPY comes in at #19 by 3-year correlation. The last year tells two different stories: CMI led by 24.5 percentage points, +45.1% for CMI against +20.6% for SPY. Across three years, the rolling one-year figure varied moderately, from 0.35 to 0.84. Note the risk asymmetry: CMI runs 1.8 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.
CMI vs SPY: side by side
| CMI (Cummins) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | +45.1% | +20.6% |
| 5-year return | +169.6% | +82.4% |
| Volatility (ann.) | 25.9% | 14.5% |
| Beta vs S&P 500 | 1.05 | 1.00 |
| Max drawdown (3Y) | -30.5% | -18.8% |
| Market cap | $79.0B | – |
| P/E (trailing) | 29.6 | – |
| Dividend yield | 1.38% | 1.01% |
| Expense ratio | – | 0.09% |
| Assets under management | – | $795.3B |
| Sector / category | Industrials | 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 | CMI | SPY |
|---|---|---|
| 2022 | +14.1% | -18.2% |
| 2023 | +1.7% | +26.2% |
| 2024 | +48.9% | +24.9% |
| 2025 | +49.4% | +17.7% |
| 2026 | +13.6% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Fund exposure
A structural note: 0.12% of SPY is CMI itself, so the fund partly moves with the stock by construction.
Are CMI and SPY good diversifiers for each other?
Only partially. A correlation of 0.59 means CMI and SPY share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
FAQ
What is the correlation between CMI and SPY?
Using weekly returns as of 2026-08-27: 0.59 over 3 years, with 0.41 over the last year and 0.61 over 5 years.
Is SPY a good diversifier for CMI?
Only partially. A correlation of 0.59 means CMI and SPY share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
What does a correlation of 0.59 mean?
On the −1 to +1 scale, 0.59 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.
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Related comparisons
Hubs: CMI correlations · SPY correlations
