FSS vs NPO: Correlation
Federal Signal Corporation (FSS) and Enpro Inc. (NPO) show a strong relationship: their 3-year correlation of weekly returns is 0.61.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are FSS and NPO?
Across a 3-year window, the weekly returns of FSS and NPO correlate at 0.61, strong. The link has loosened recently: the 1-year correlation (0.40) runs below the 3-year figure (0.61). Stretching to 5 years gives 0.62, with an annualized covariance of 655.8 %².
Among the 15 assets we track against FSS, NPO ranks #5 by 3-year correlation. Correlation aside, the last 12 months split them widely, with NPO ahead by 42.4 points (-5.3% versus +37.1%).
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.
FSS vs NPO: side by side
| FSS (Federal Signal Corporation) | NPO (Enpro Inc.) | |
|---|---|---|
| 1-year return | -5.3% | +37.1% |
| 5-year return | +203.9% | +270.5% |
| Volatility (ann.) | 31.2% | 34.4% |
| Beta vs S&P 500 | 1.02 | 1.27 |
| Max drawdown (3Y) | -31.5% | -33.7% |
| Market cap | $7.3B | $6.5B |
| P/E (trailing) | 26.2 | 149.1 |
| Dividend yield | 0.48% | 0.41% |
| Sector / category | US Listed | US Listed |
Year-by-year returns
| Year | FSS | NPO |
|---|---|---|
| 2022 | +8.2% | -0.2% |
| 2023 | +66.3% | +45.6% |
| 2024 | +21.1% | +10.9% |
| 2025 | +18.2% | +25.0% |
| 2026 | +11.3% | +44.5% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are FSS and NPO good diversifiers for each other?
To a limited degree. At 0.61 the two still catch most of the same waves, so the pair smooths returns a little without insulating either from a shared selloff.
FAQ
What is the correlation between FSS and NPO?
As of 2026-08-27, the correlation of weekly returns between FSS and NPO is 0.61 over 3 years, 0.40 over 1 year and 0.62 over 5 years.
Is NPO a good diversifier for FSS?
To a limited degree. At 0.61 the two still catch most of the same waves, so the pair smooths returns a little without insulating either from a shared selloff.
What does a correlation of 0.61 mean?
On the −1 to +1 scale, 0.61 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/fss-vs-npo.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/fss-vs-npo/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: FSS correlations · NPO correlations
