MDY vs SPRB: Correlation
How closely do SPDR S&P MidCap 400 ETF (MDY) and Spruce Biosciences, Inc. (SPRB) trade together? Their weekly returns over three years give a correlation of -0.13, which is negative.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are MDY and SPRB?
On 3 years of weekly data the MDY/SPRB correlation comes out at -0.13, negative, meaning they tend to move in opposite directions. Lately the two have drifted apart, with the 1-year correlation at -0.31 versus -0.13 over 3 years. The 5-year figure is -0.08, and annualized covariance runs at -2384.5 %².
By 3-year correlation, SPRB places #352 of the 359 assets tracked against MDY. Their recent paths diverged sharply: over the last 12 months SPRB outperformed by 728.0 percentage points (+18.3% for MDY against +746.3% for SPRB). Risk is not evenly split, since SPRB carries 65.8 times the volatility of the other side.
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.
MDY vs SPRB: side by side
| MDY (SPDR S&P MidCap 400 ETF) | SPRB (Spruce Biosciences, Inc.) | |
|---|---|---|
| 1-year return | +18.3% | +746.3% |
| 5-year return | +47.5% | -99.8% |
| Volatility (ann.) | 16.5% | 1086.4% |
| Beta vs S&P 500 | 0.91 | -7.82 |
| Max drawdown (3Y) | -24.0% | -100.0% |
| Market cap | – | $0.2B |
| P/E (trailing) | – | – |
| Dividend yield | 1.02% | 0.00% |
| Expense ratio | 0.23% | – |
| Assets under management | $26.5B | – |
| Sector / category | ETF · US Small & Mid Cap | US Listed |
MDY is a Mid-Cap Blend fund from State Street Investment Management: $26.5B under management, 400 holdings, a 0.23% expense ratio, a 1.02% trailing dividend yield.
Year-by-year returns
| Year | MDY | SPRB |
|---|---|---|
| 2022 | -13.3% | -75.4% |
| 2023 | +16.1% | +167.1% |
| 2024 | +13.6% | -85.7% |
| 2025 | +7.2% | -96.3% |
| 2026 | +16.4% | -27.3% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are MDY and SPRB good diversifiers for each other?
Yes. With a correlation of -0.13, MDY and SPRB have moved largely independently, which makes them a genuinely diversifying pair by historical standards.
FAQ
What is the correlation between MDY and SPRB?
The MDY/SPRB correlation stands at -0.13 on a 3-year window (1 year: -0.31, 5 years: -0.08), computed from weekly returns as of 2026-08-27.
Is SPRB a good diversifier for MDY?
Yes. With a correlation of -0.13, MDY and SPRB have moved largely independently, which makes them a genuinely diversifying pair by historical standards.
What does a correlation of -0.13 mean?
On the −1 to +1 scale, -0.13 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.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/mdy-vs-sprb.json
Markdown for the live badge, attribution link included:
[](https://www.pairbook.io/pair/mdy-vs-sprb/)
Free with attribution; caching and terms are described in the API documentation.
Related comparisons
Hubs: MDY correlations · SPRB correlations
