MDY vs PLUS: Correlation
Measured on weekly returns over the past three years, SPDR S&P MidCap 400 ETF (MDY) and ePlus inc. (PLUS) carry a correlation of 0.55, a moderate link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are MDY and PLUS?
Across a 3-year window, the weekly returns of MDY and PLUS correlate at 0.55, moderate. The link has loosened recently: the 1-year correlation (0.27) runs below the 3-year figure (0.55). Stretching to 5 years gives 0.57, with an annualized covariance of 302.3 %².
Among the 359 assets we track against MDY, PLUS ranks #250 by 3-year correlation. Neither side won the trailing year by much: +18.3% against +22.3%. Risk is not evenly split, since PLUS carries 2.0 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 PLUS: side by side
| MDY (SPDR S&P MidCap 400 ETF) | PLUS (ePlus inc.) | |
|---|---|---|
| 1-year return | +18.3% | +22.3% |
| 5-year return | +47.5% | +64.0% |
| Volatility (ann.) | 16.5% | 33.2% |
| Beta vs S&P 500 | 0.91 | 1.04 |
| Max drawdown (3Y) | -24.0% | -46.1% |
| Market cap | – | $2.3B |
| P/E (trailing) | – | 18.8 |
| Dividend yield | 1.02% | 1.18% |
| Expense ratio | 0.23% | – |
| Assets under management | $26.5B | – |
| Sector / category | ETF · US Small & Mid Cap | US Listed |
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 | PLUS |
|---|---|---|
| 2022 | -13.3% | -17.8% |
| 2023 | +16.1% | +80.3% |
| 2024 | +13.6% | -7.5% |
| 2025 | +7.2% | +19.4% |
| 2026 | +16.4% | +0.9% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are MDY and PLUS good diversifiers for each other?
Only partially. A correlation of 0.55 means MDY and PLUS share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
FAQ
What is the correlation between MDY and PLUS?
The MDY/PLUS correlation stands at 0.55 on a 3-year window (1 year: 0.27, 5 years: 0.57), computed from weekly returns as of 2026-08-27.
Is PLUS a good diversifier for MDY?
Only partially. A correlation of 0.55 means MDY and PLUS share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
What does a correlation of 0.55 mean?
A reading of 0.55 sits on a scale from −1 (opposite moves) through 0 (unrelated) to +1 (identical moves). Correlation captures direction, not magnitude or performance.
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Related comparisons
Hubs: MDY correlations · PLUS correlations
