NPKI vs SPY: Correlation
How closely do NPK International Inc. (NPKI) and SPDR S&P 500 ETF Trust (SPY) trade together? Their weekly returns over three years give a correlation of 0.31, which is moderate.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are NPKI and SPY?
Across a 3-year window, the weekly returns of NPKI and SPY correlate at 0.31, moderate. The past 12 months show a weaker link (0.15) than the 3-year average (0.31). Stretching to 5 years gives 0.22, with an annualized covariance of 183.4 %².
SPY is close to the least connected end of NPKI's tracked universe, ranking #11 of 15. Over the last 12 months NPKI came out ahead by 11.0 percentage points (+31.6% against +20.6%). Note the risk asymmetry: NPKI runs 2.8 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.
NPKI vs SPY: side by side
| NPKI (NPK International Inc.) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | +31.6% | +20.6% |
| 5-year return | +429.3% | +82.4% |
| Volatility (ann.) | 41.0% | 14.5% |
| Beta vs S&P 500 | 0.88 | 1.00 |
| Max drawdown (3Y) | -42.1% | -18.8% |
| Market cap | $1.2B | – |
| P/E (trailing) | 28.8 | – |
| Dividend yield | 0.00% | 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 | NPKI | SPY |
|---|---|---|
| 2022 | +41.2% | -18.2% |
| 2023 | +60.0% | +26.2% |
| 2024 | +15.5% | +24.9% |
| 2025 | +55.4% | +17.7% |
| 2026 | +13.7% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are NPKI and SPY good diversifiers for each other?
A fair diversifier. At 0.31, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
FAQ
What is the correlation between NPKI and SPY?
The NPKI/SPY correlation stands at 0.31 on a 3-year window (1 year: 0.15, 5 years: 0.22), computed from weekly returns as of 2026-08-27.
Is SPY a good diversifier for NPKI?
A fair diversifier. At 0.31, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
What does a correlation of 0.31 mean?
A reading of 0.31 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: NPKI correlations · SPY correlations
