MDY vs PATK: Correlation
Measured on weekly returns over the past three years, SPDR S&P MidCap 400 ETF (MDY) and Patrick Industries, Inc. (PATK) carry a correlation of 0.66, a strong link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are MDY and PATK?
On 3 years of weekly data the MDY/PATK correlation comes out at 0.66, strong. The past 12 months show a weaker link (0.54) than the 3-year average (0.66). The 5-year figure is 0.64, and annualized covariance runs at 387.4 %².
By 3-year correlation, PATK places #102 of the 359 assets tracked against MDY. Their recent paths diverged sharply: over the last 12 months MDY outperformed by 44.1 percentage points (+18.3% for MDY against -25.8% for PATK). Note the risk asymmetry: PATK runs 2.2 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.
MDY vs PATK: side by side
| MDY (SPDR S&P MidCap 400 ETF) | PATK (Patrick Industries, Inc.) | |
|---|---|---|
| 1-year return | +18.3% | -25.8% |
| 5-year return | +47.5% | +62.2% |
| Volatility (ann.) | 16.5% | 35.5% |
| Beta vs S&P 500 | 0.91 | 1.04 |
| Max drawdown (3Y) | -24.0% | -42.9% |
| Market cap | – | $2.7B |
| P/E (trailing) | – | 19.9 |
| Dividend yield | 1.02% | 2.16% |
| 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 | PATK |
|---|---|---|
| 2022 | -13.3% | -23.1% |
| 2023 | +16.1% | +69.6% |
| 2024 | +13.6% | +26.5% |
| 2025 | +7.2% | +32.7% |
| 2026 | +16.4% | -22.3% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are MDY and PATK good diversifiers for each other?
Somewhat, no more. With 0.66 correlation, most large moves hit both names, and the diversification benefit stays modest.
FAQ
What is the correlation between MDY and PATK?
The MDY/PATK correlation stands at 0.66 on a 3-year window (1 year: 0.54, 5 years: 0.64), computed from weekly returns as of 2026-08-27.
Is PATK a good diversifier for MDY?
Somewhat, no more. With 0.66 correlation, most large moves hit both names, and the diversification benefit stays modest.
What does a correlation of 0.66 mean?
On the −1 to +1 scale, 0.66 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: MDY correlations · PATK correlations
