MDY vs MWA: Correlation
SPDR S&P MidCap 400 ETF (MDY) and MUELLER WATER PRODUCTS (MWA) show a moderate relationship: their 3-year correlation of weekly returns is 0.59.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are MDY and MWA?
Over the past 3 years, MDY and MWA moved with a correlation of 0.59, which is moderate. Little has changed lately, as the 1-year reading of 0.58 lands near the 3-year figure. Over 5 years the correlation is 0.63, and the annualized covariance of weekly returns is 307.7 %².
Within MDY's tracked universe of 359 assets, MWA comes in at #193 by 3-year correlation. Their recent paths diverged sharply: over the last 12 months MDY outperformed by 26.7 percentage points (+18.3% for MDY against -8.4% for MWA). One caveat on sizing: MWA is 1.9 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.
MDY vs MWA: side by side
| MDY (SPDR S&P MidCap 400 ETF) | MWA (MUELLER WATER PRODUCTS) | |
|---|---|---|
| 1-year return | +18.3% | -8.4% |
| 5-year return | +47.5% | +59.7% |
| Volatility (ann.) | 16.5% | 31.5% |
| Beta vs S&P 500 | 0.91 | 0.96 |
| Max drawdown (3Y) | -24.0% | -19.2% |
| Market cap | – | $3.9B |
| P/E (trailing) | – | 17.4 |
| Dividend yield | 1.02% | 1.10% |
| 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 | MWA |
|---|---|---|
| 2022 | -13.3% | -23.8% |
| 2023 | +16.1% | +36.3% |
| 2024 | +13.6% | +58.4% |
| 2025 | +7.2% | +7.0% |
| 2026 | +16.4% | +4.6% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are MDY and MWA good diversifiers for each other?
Somewhat, no more. With 0.59 correlation, most large moves hit both names, and the diversification benefit stays modest.
FAQ
What is the correlation between MDY and MWA?
Using weekly returns as of 2026-08-27: 0.59 over 3 years, with 0.58 over the last year and 0.63 over 5 years.
Is MWA a good diversifier for MDY?
Somewhat, no more. With 0.59 correlation, most large moves hit both names, and the diversification benefit stays modest.
What does a correlation of 0.59 mean?
Correlation ranges from −1 to +1. Values near +1 mean two assets move together, near 0 that they move independently, and negative values that they tend to move in opposite directions. It measures co-movement, not performance.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/mdy-vs-mwa.json
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Related comparisons
Hubs: MDY correlations · MWA correlations
