BBSI vs SPY: Correlation
Measured on weekly returns over the past three years, Barrett Business Services, Inc. (BBSI) and SPDR S&P 500 ETF Trust (SPY) carry a correlation of 0.30, a moderate link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are BBSI and SPY?
Over the past 3 years, BBSI and SPY moved with a correlation of 0.30, which is moderate. The link has loosened recently: the 1-year correlation (-0.02) runs below the 3-year figure (0.30). Over 5 years the correlation is 0.37, and the annualized covariance of weekly returns is 133.6 %².
Among the 16 assets we track against BBSI, SPY ranks #8 by 3-year correlation. Their recent paths diverged sharply: over the last 12 months SPY outperformed by 49.4 percentage points (-28.8% for BBSI against +20.6% for SPY). Note the risk asymmetry: BBSI runs 2.1 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.
BBSI vs SPY: side by side
| BBSI (Barrett Business Services, Inc.) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | -28.8% | +20.6% |
| 5-year return | +89.3% | +82.4% |
| Volatility (ann.) | 30.3% | 14.5% |
| Beta vs S&P 500 | 0.64 | 1.00 |
| Max drawdown (3Y) | -45.3% | -18.8% |
| Market cap | $0.8B | – |
| P/E (trailing) | 25.3 | – |
| Dividend yield | 0.94% | 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 | BBSI | SPY |
|---|---|---|
| 2022 | +37.1% | -18.2% |
| 2023 | +25.8% | +26.2% |
| 2024 | +51.4% | +24.9% |
| 2025 | -16.0% | +17.7% |
| 2026 | -4.9% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are BBSI and SPY good diversifiers for each other?
A fair diversifier. At 0.30, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
FAQ
What is the correlation between BBSI and SPY?
The BBSI/SPY correlation stands at 0.30 on a 3-year window (1 year: -0.02, 5 years: 0.37), computed from weekly returns as of 2026-08-27.
Is SPY a good diversifier for BBSI?
A fair diversifier. At 0.30, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
What does a correlation of 0.30 mean?
A reading of 0.30 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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Hubs: BBSI correlations · SPY correlations
