CMS vs POR: Correlation
How closely do CMS Energy (CMS) and Portland General Electric Co (POR) trade together? Their weekly returns over three years give a correlation of 0.73, which is strong.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are CMS and POR?
Across a 3-year window, the weekly returns of CMS and POR correlate at 0.73, strong. Recent behaviour matches the longer record: 0.80 over 1 year against 0.73 over 3. Stretching to 5 years gives 0.76, with an annualized covariance of 216.7 %².
Within CMS's tracked universe of 42 assets, POR comes in at #15 by 3-year correlation. Correlation aside, the last 12 months split them widely, with POR ahead by 23.4 points (-2.4% versus +21.0%).
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 POR: side by side
| CMS (CMS Energy) | POR (Portland General Electric Co) | |
|---|---|---|
| 1-year return | -2.4% | +21.0% |
| 5-year return | +23.8% | +20.7% |
| Volatility (ann.) | 16.2% | 18.5% |
| Beta vs S&P 500 | -0.01 | 0.10 |
| Max drawdown (3Y) | -13.2% | -16.3% |
| Market cap | $21.4B | $5.9B |
| P/E (trailing) | 20.8 | 22.2 |
| Dividend yield | 3.21% | 4.24% |
| Sector / category | Utilities | US Listed |
Year-by-year returns
| Year | CMS | POR |
|---|---|---|
| 2022 | +0.2% | -4.0% |
| 2023 | -5.2% | -7.7% |
| 2024 | +18.6% | +5.3% |
| 2025 | +8.1% | +15.4% |
| 2026 | +0.0% | +6.1% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are CMS and POR good diversifiers for each other?
Only partially. A correlation of 0.73 means CMS and POR 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 CMS and POR?
As of 2026-08-27, the correlation of weekly returns between CMS and POR is 0.73 over 3 years, 0.80 over 1 year and 0.76 over 5 years.
Is POR a good diversifier for CMS?
Only partially. A correlation of 0.73 means CMS and POR share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
What does a correlation of 0.73 mean?
On the −1 to +1 scale, 0.73 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-por.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/cms-vs-por/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: CMS correlations · POR correlations
