MBRX vs SPY: Correlation
Measured on weekly returns over the past three years, Moleculin Biotech, Inc. (MBRX) and SPDR S&P 500 ETF Trust (SPY) carry a correlation of 0.10, a weak link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are MBRX and SPY?
Over the past 3 years, MBRX and SPY moved with a correlation of 0.10, which is weak. Lately the two have drifted apart, with the 1-year correlation at -0.12 versus 0.10 over 3 years. Over 5 years the correlation is 0.15, and the annualized covariance of weekly returns is 229.8 %².
Among the 13 assets we track against MBRX, SPY ranks #8 by 3-year correlation. The last year tells two different stories: SPY led by 116.1 percentage points, -95.5% for MBRX against +20.6% for SPY. One caveat on sizing: MBRX is 11.1 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.
MBRX vs SPY: side by side
| MBRX (Moleculin Biotech, Inc.) | SPY (SPDR S&P 500 ETF Trust) | |
|---|---|---|
| 1-year return | -95.5% | +20.6% |
| 5-year return | -99.9% | +82.4% |
| Volatility (ann.) | 160.4% | 14.5% |
| Beta vs S&P 500 | 1.10 | 1.00 |
| Max drawdown (3Y) | -99.9% | -18.8% |
| Market cap | – | – |
| P/E (trailing) | 0.0 | – |
| 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 | MBRX | SPY |
|---|---|---|
| 2022 | -43.0% | -18.2% |
| 2023 | -19.1% | +26.2% |
| 2024 | -86.8% | +24.9% |
| 2025 | -92.2% | +17.7% |
| 2026 | -79.2% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are MBRX and SPY good diversifiers for each other?
Yes. With a correlation of 0.10, MBRX and SPY have moved largely independently, which makes them a genuinely diversifying pair by historical standards.
FAQ
What is the correlation between MBRX and SPY?
The MBRX/SPY correlation stands at 0.10 on a 3-year window (1 year: -0.12, 5 years: 0.15), computed from weekly returns as of 2026-08-27.
Is SPY a good diversifier for MBRX?
Yes. With a correlation of 0.10, MBRX and SPY have moved largely independently, which makes them a genuinely diversifying pair by historical standards.
What does a correlation of 0.10 mean?
A reading of 0.10 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: MBRX correlations · SPY correlations
