MDY vs XYL: Correlation
SPDR S&P MidCap 400 ETF (MDY) and Xylem Inc. (XYL) show a strong relationship: their 3-year correlation of weekly returns is 0.66.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are MDY and XYL?
Across a 3-year window, the weekly returns of MDY and XYL correlate at 0.66, strong. The past 12 months show a weaker link (0.49) than the 3-year average (0.66). Stretching to 5 years gives 0.67, with an annualized covariance of 258.4 %².
Among the 359 assets we track against MDY, XYL ranks #106 by 3-year correlation. The last year tells two different stories: MDY led by 39.4 percentage points, +18.3% for MDY against -21.1% for XYL. On a rolling one-year basis the correlation drifted between 0.31 and 0.80, a moderate band.
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 XYL: side by side
| MDY (SPDR S&P MidCap 400 ETF) | XYL (Xylem Inc.) | |
|---|---|---|
| 1-year return | +18.3% | -21.1% |
| 5-year return | +47.5% | -12.5% |
| Volatility (ann.) | 16.5% | 23.9% |
| Beta vs S&P 500 | 0.91 | 0.96 |
| Max drawdown (3Y) | -24.0% | -30.0% |
| Market cap | – | $26.3B |
| P/E (trailing) | – | 26.8 |
| Dividend yield | 1.02% | 1.47% |
| Expense ratio | 0.23% | – |
| Assets under management | $26.5B | – |
| Sector / category | ETF · US Small & Mid Cap | Industrials |
On the fund side, MDY sits in the Mid-Cap Blend category at State Street Investment Management, with $26.5B under management, 400 holdings, a 0.23% expense ratio, a 1.02% trailing dividend yield.
Year-by-year returns
| Year | MDY | XYL |
|---|---|---|
| 2022 | -13.3% | -6.6% |
| 2023 | +16.1% | +4.8% |
| 2024 | +13.6% | +2.6% |
| 2025 | +7.2% | +18.8% |
| 2026 | +16.4% | -16.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are MDY and XYL good diversifiers for each other?
To a limited degree. At 0.66 the two still catch most of the same waves, so the pair smooths returns a little without insulating either from a shared selloff.
FAQ
What is the correlation between MDY and XYL?
The MDY/XYL correlation stands at 0.66 on a 3-year window (1 year: 0.49, 5 years: 0.67), computed from weekly returns as of 2026-08-27.
Is XYL a good diversifier for MDY?
To a limited degree. At 0.66 the two still catch most of the same waves, so the pair smooths returns a little without insulating either from a shared selloff.
What does a correlation of 0.66 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-xyl.json
Markdown for the live badge, attribution link included:
[](https://www.pairbook.io/pair/mdy-vs-xyl/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: MDY correlations · XYL correlations
