GBDC vs SPY: Correlation
How closely do Golub Capital BDC, Inc. - Closed End Fund (GBDC) and SPDR S&P 500 ETF Trust (SPY) trade together? Their weekly returns over three years give a correlation of 0.43, which is moderate.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are GBDC and SPY?
On 3 years of weekly data the GBDC/SPY correlation comes out at 0.43, moderate. The relationship has been stable: the 1-year correlation (0.34) sits close to the 3-year figure. The 5-year figure is 0.47, and annualized covariance runs at 97.4 %².
Among the 17 assets we track against GBDC, SPY ranks #11 by 3-year correlation. The last year tells two different stories: SPY led by 21.8 percentage points, -1.2% for GBDC against +20.6% for SPY.
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.
GBDC vs SPY: side by side
| GBDC (Golub Capital BDC, Inc. - Closed End Fund) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | -1.2% | +20.6% |
| 5-year return | +39.0% | +82.4% |
| Volatility (ann.) | 15.8% | 14.5% |
| Beta vs S&P 500 | 0.47 | 1.00 |
| Max drawdown (3Y) | -18.2% | -18.8% |
| Market cap | $3.4B | – |
| P/E (trailing) | 19.8 | – |
| Dividend yield | 10.98% | 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 | GBDC | SPY |
|---|---|---|
| 2022 | -7.0% | -18.2% |
| 2023 | +27.7% | +26.2% |
| 2024 | +13.6% | +24.9% |
| 2025 | -0.5% | +17.7% |
| 2026 | +1.5% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are GBDC and SPY good diversifiers for each other?
Reasonably. At 0.43, GBDC and SPY keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
FAQ
What is the correlation between GBDC and SPY?
The GBDC/SPY correlation stands at 0.43 on a 3-year window (1 year: 0.34, 5 years: 0.47), computed from weekly returns as of 2026-08-27.
Is SPY a good diversifier for GBDC?
Reasonably. At 0.43, GBDC and SPY keep a meaningful degree of independence, and combining them has historically reduced portfolio volatility.
What does a correlation of 0.43 mean?
On the −1 to +1 scale, 0.43 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: GBDC correlations · SPY correlations
