NWE vs SPY: Correlation
How closely do NorthWestern Energy Group, Inc. (NWE) and SPDR S&P 500 ETF Trust (SPY) trade together? Their weekly returns over three years give a correlation of 0.18, which is weak.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are NWE and SPY?
On 3 years of weekly data the NWE/SPY correlation comes out at 0.18, weak. Little has changed lately, as the 1-year reading of 0.17 lands near the 3-year figure. The 5-year figure is 0.28, and annualized covariance runs at 53.7 %².
Among the 13 assets we track against NWE, SPY sits near the bottom by co-movement, at rank #9. On 12-month performance NWE holds a 7.9-point edge, +28.5% against +20.6%.
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.
NWE vs SPY: side by side
| NWE (NorthWestern Energy Group, Inc.) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | +28.5% | +20.6% |
| 5-year return | +41.5% | +82.4% |
| Volatility (ann.) | 20.9% | 14.5% |
| Beta vs S&P 500 | 0.26 | 1.00 |
| Max drawdown (3Y) | -13.6% | -18.8% |
| Market cap | $4.4B | – |
| P/E (trailing) | 25.6 | – |
| Dividend yield | 3.72% | 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 | NWE | SPY |
|---|---|---|
| 2022 | +8.5% | -18.2% |
| 2023 | -10.1% | +26.2% |
| 2024 | +10.5% | +24.9% |
| 2025 | +26.4% | +17.7% |
| 2026 | +13.2% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are NWE and SPY good diversifiers for each other?
Yes: at 0.18, the two have gone their own ways historically, which is what genuine diversification looks like.
FAQ
What is the correlation between NWE and SPY?
The NWE/SPY correlation stands at 0.18 on a 3-year window (1 year: 0.17, 5 years: 0.28), computed from weekly returns as of 2026-08-27.
Is SPY a good diversifier for NWE?
Yes: at 0.18, the two have gone their own ways historically, which is what genuine diversification looks like.
What does a correlation of 0.18 mean?
A reading of 0.18 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: NWE correlations · SPY correlations
