BELFA vs SPY: Correlation
Measured on weekly returns over the past three years, Bel Fuse Inc. (BELFA) and SPDR S&P 500 ETF Trust (SPY) carry a correlation of 0.39, a moderate link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are BELFA and SPY?
Over the past 3 years, BELFA and SPY moved with a correlation of 0.39, which is moderate. Little has changed lately, as the 1-year reading of 0.33 lands near the 3-year figure. Over 5 years the correlation is 0.38, and the annualized covariance of weekly returns is 270.9 %².
SPY is close to the least connected end of BELFA's tracked universe, ranking #6 of 10. The last year tells two different stories: BELFA led by 59.9 percentage points, +80.5% for BELFA against +20.6% for SPY. Note the risk asymmetry: BELFA runs 3.4 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.
BELFA vs SPY: side by side
| BELFA (Bel Fuse Inc.) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | +80.5% | +20.6% |
| 5-year return | +1292.5% | +82.4% |
| Volatility (ann.) | 48.6% | 14.5% |
| Beta vs S&P 500 | 1.30 | 1.00 |
| Max drawdown (3Y) | -43.4% | -18.8% |
| Market cap | $3.1B | – |
| P/E (trailing) | 54.3 | – |
| Dividend yield | 0.11% | 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 | BELFA | SPY |
|---|---|---|
| 2022 | +117.0% | -18.2% |
| 2023 | +102.0% | +26.2% |
| 2024 | +39.8% | +24.9% |
| 2025 | +69.0% | +17.7% |
| 2026 | +40.6% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are BELFA and SPY good diversifiers for each other?
Yes, to a useful degree: a correlation of 0.39 leaves real independence between the two, which historically damped combined volatility.
FAQ
What is the correlation between BELFA and SPY?
As of 2026-08-27, the correlation of weekly returns between BELFA and SPY is 0.39 over 3 years, 0.33 over 1 year and 0.38 over 5 years.
Is SPY a good diversifier for BELFA?
Yes, to a useful degree: a correlation of 0.39 leaves real independence between the two, which historically damped combined volatility.
What does a correlation of 0.39 mean?
On the −1 to +1 scale, 0.39 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: BELFA correlations · SPY correlations
