MBBC vs SPY: Correlation
Marathon Bancorp, Inc. (MBBC) and SPDR S&P 500 ETF Trust (SPY) show a near-zero relationship: their 3-year correlation of weekly returns is -0.03.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are MBBC and SPY?
On 3 years of weekly data the MBBC/SPY correlation comes out at -0.03, near zero, meaning they move largely independently. Recent behaviour matches the longer record: 0.05 over 1 year against -0.03 over 3. The 5-year figure is 0.01, and annualized covariance runs at -13.8 %².
Out of 13 assets tracked against MBBC, SPY lands near the bottom at #9. Their recent paths diverged sharply: over the last 12 months MBBC outperformed by 27.7 percentage points (+48.3% for MBBC against +20.6% for SPY). One caveat on sizing: MBBC is 2.2 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.
MBBC vs SPY: side by side
| MBBC (Marathon Bancorp, Inc.) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | +48.3% | +20.6% |
| 5-year return | +103.0% | +82.4% |
| Volatility (ann.) | 31.3% | 14.5% |
| Beta vs S&P 500 | -0.07 | 1.00 |
| Max drawdown (3Y) | -28.3% | -18.8% |
| Market cap | – | – |
| P/E (trailing) | 36.7 | – |
| 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 | MBBC | SPY |
|---|---|---|
| 2022 | +4.7% | -18.2% |
| 2023 | -17.0% | +26.2% |
| 2024 | +49.9% | +24.9% |
| 2025 | +19.2% | +17.7% |
| 2026 | +26.6% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are MBBC and SPY good diversifiers for each other?
By historical standards, yes. A correlation of -0.03 means the two rarely move for the same reasons.
FAQ
What is the correlation between MBBC and SPY?
Using weekly returns as of 2026-08-27: -0.03 over 3 years, with 0.05 over the last year and 0.01 over 5 years.
Is SPY a good diversifier for MBBC?
By historical standards, yes. A correlation of -0.03 means the two rarely move for the same reasons.
What does a correlation of -0.03 mean?
On the −1 to +1 scale, -0.03 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: MBBC correlations · SPY correlations
