FSS vs SPY: Correlation
Measured on weekly returns over the past three years, Federal Signal Corporation (FSS) and SPDR S&P 500 ETF Trust (SPY) carry a correlation of 0.47, a moderate link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are FSS and SPY?
Across a 3-year window, the weekly returns of FSS and SPY correlate at 0.47, moderate. The past 12 months show a weaker link (0.23) than the 3-year average (0.47). Stretching to 5 years gives 0.53, with an annualized covariance of 213.4 %².
By 3-year correlation, SPY places #9 of the 15 assets tracked against FSS. The last year tells two different stories: SPY led by 25.9 percentage points, -5.3% for FSS against +20.6% for SPY. Risk is not evenly split, since FSS carries 2.2 times the volatility of the other side.
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 SPY: side by side
| FSS (Federal Signal Corporation) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | -5.3% | +20.6% |
| 5-year return | +203.9% | +82.4% |
| Volatility (ann.) | 31.2% | 14.5% |
| Beta vs S&P 500 | 1.02 | 1.00 |
| Max drawdown (3Y) | -31.5% | -18.8% |
| Market cap | $7.3B | – |
| P/E (trailing) | 26.2 | – |
| Dividend yield | 0.48% | 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 | FSS | SPY |
|---|---|---|
| 2022 | +8.2% | -18.2% |
| 2023 | +66.3% | +26.2% |
| 2024 | +21.1% | +24.9% |
| 2025 | +18.2% | +17.7% |
| 2026 | +11.3% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are FSS and SPY good diversifiers for each other?
Reasonably. At 0.47, FSS and SPY keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
FAQ
What is the correlation between FSS and SPY?
The FSS/SPY correlation stands at 0.47 on a 3-year window (1 year: 0.23, 5 years: 0.53), computed from weekly returns as of 2026-08-27.
Is SPY a good diversifier for FSS?
Reasonably. At 0.47, FSS and SPY keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
What does a correlation of 0.47 mean?
A reading of 0.47 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: FSS correlations · SPY correlations
