FSTR vs SPY: Correlation
L.B. Foster Company (FSTR) and SPDR S&P 500 ETF Trust (SPY) show a moderate relationship: their 3-year correlation of weekly returns is 0.38.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are FSTR and SPY?
Over the past 3 years, FSTR and SPY moved with a correlation of 0.38, which is moderate. Lately the two have drifted apart, with the 1-year correlation at 0.27 versus 0.38 over 3 years. Over 5 years the correlation is 0.35, and the annualized covariance of weekly returns is 257.0 %².
Among the 16 assets we track against FSTR, SPY ranks #9 by 3-year correlation. The last year tells two different stories: FSTR led by 22.2 percentage points, +42.8% for FSTR against +20.6% for SPY. One caveat on sizing: FSTR is 3.2 times as volatile as the other leg, so an equal-dollar split is far from equal-risk.
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.
FSTR vs SPY: side by side
| FSTR (L.B. Foster Company) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | +42.8% | +20.6% |
| 5-year return | +119.1% | +82.4% |
| Volatility (ann.) | 46.4% | 14.5% |
| Beta vs S&P 500 | 1.23 | 1.00 |
| Max drawdown (3Y) | -45.9% | -18.8% |
| Market cap | $0.4B | – |
| P/E (trailing) | 35.4 | – |
| 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 | FSTR | SPY |
|---|---|---|
| 2022 | -29.6% | -18.2% |
| 2023 | +127.2% | +26.2% |
| 2024 | +22.3% | +24.9% |
| 2025 | +0.2% | +17.7% |
| 2026 | +40.4% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are FSTR and SPY good diversifiers for each other?
Yes, to a useful degree: a correlation of 0.38 leaves real independence between the two, which historically damped combined volatility.
FAQ
What is the correlation between FSTR and SPY?
Using weekly returns as of 2026-08-27: 0.38 over 3 years, with 0.27 over the last year and 0.35 over 5 years.
Is SPY a good diversifier for FSTR?
Yes, to a useful degree: a correlation of 0.38 leaves real independence between the two, which historically damped combined volatility.
What does a correlation of 0.38 mean?
On the −1 to +1 scale, 0.38 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.
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Related comparisons
Hubs: FSTR correlations · SPY correlations
