ENS vs MDY: Correlation
EnerSys (ENS) and SPDR S&P MidCap 400 ETF (MDY) show a moderate relationship: their 3-year correlation of weekly returns is 0.58.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are ENS and MDY?
Over the past 3 years, ENS and MDY moved with a correlation of 0.58, which is moderate. The past 12 months show a weaker link (0.32) than the 3-year average (0.58). Over 5 years the correlation is 0.65, and the annualized covariance of weekly returns is 289.0 %².
By 3-year correlation, MDY places #5 of the 11 assets tracked against ENS. Correlation aside, the last 12 months split them widely, with ENS ahead by 69.6 points (+87.9% versus +18.3%). Risk is not evenly split, since ENS carries 1.8 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.
ENS vs MDY: side by side
| ENS (EnerSys) | MDY (SPDR S&P MidCap 400 ETF) | |
|---|---|---|
| 1-year return | +87.9% | +18.3% |
| 5-year return | +131.9% | +47.5% |
| Volatility (ann.) | 30.1% | 16.5% |
| Beta vs S&P 500 | 1.09 | 0.91 |
| Max drawdown (3Y) | -28.2% | -24.0% |
| Market cap | $6.9B | – |
| P/E (trailing) | 20.7 | – |
| Dividend yield | 0.54% | 1.02% |
| Expense ratio | – | 0.23% |
| Assets under management | – | $26.5B |
| Sector / category | US Listed | ETF · US Small & Mid Cap |
MDY, State Street Investment Management's Mid-Cap Blend fund, carries $26.5B under management, 400 holdings, a 0.23% expense ratio, a 1.02% trailing dividend yield.
Year-by-year returns
| Year | ENS | MDY |
|---|---|---|
| 2022 | -5.6% | -13.3% |
| 2023 | +37.9% | +16.1% |
| 2024 | -7.6% | +13.6% |
| 2025 | +60.3% | +7.2% |
| 2026 | +30.5% | +16.4% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Fund exposure
A structural note: 0.19% of MDY is ENS itself, so the fund partly moves with the stock by construction.
Are ENS and MDY good diversifiers for each other?
To a limited degree. At 0.58 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 ENS and MDY?
Using weekly returns as of 2026-08-27: 0.58 over 3 years, with 0.32 over the last year and 0.65 over 5 years.
Is MDY a good diversifier for ENS?
To a limited degree. At 0.58 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 0.58 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.
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Related comparisons
Hubs: ENS correlations · MDY correlations
