DGII vs MDY: Correlation
How closely do Digi International Inc. (DGII) and SPDR S&P MidCap 400 ETF (MDY) trade together? Their weekly returns over three years give a correlation of 0.54, which is moderate.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are DGII and MDY?
Across a 3-year window, the weekly returns of DGII and MDY correlate at 0.54, moderate. Recent behaviour matches the longer record: 0.46 over 1 year against 0.54 over 3. Stretching to 5 years gives 0.51, with an annualized covariance of 356.5 %².
By 3-year correlation, MDY places #5 of the 10 assets tracked against DGII. The last year tells two different stories: DGII led by 107.7 percentage points, +126.0% for DGII against +18.3% for MDY. Note the risk asymmetry: DGII runs 2.4 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.
DGII vs MDY: side by side
| DGII (Digi International Inc.) | MDY (SPDR S&P MidCap 400 ETF) | |
|---|---|---|
| 1-year return | +126.0% | +18.3% |
| 5-year return | +253.2% | +47.5% |
| Volatility (ann.) | 40.0% | 16.5% |
| Beta vs S&P 500 | 1.26 | 0.91 |
| Max drawdown (3Y) | -35.2% | -24.0% |
| Market cap | $2.9B | – |
| P/E (trailing) | 60.5 | – |
| Dividend yield | 0.00% | 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 | DGII | MDY |
|---|---|---|
| 2022 | +48.8% | -13.3% |
| 2023 | -28.9% | +16.1% |
| 2024 | +16.3% | +13.6% |
| 2025 | +43.2% | +7.2% |
| 2026 | +78.9% | +16.4% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are DGII and MDY good diversifiers for each other?
Somewhat, no more. With 0.54 correlation, most large moves hit both names, and the diversification benefit stays modest.
FAQ
What is the correlation between DGII and MDY?
The DGII/MDY correlation stands at 0.54 on a 3-year window (1 year: 0.46, 5 years: 0.51), computed from weekly returns as of 2026-08-27.
Is MDY a good diversifier for DGII?
Somewhat, no more. With 0.54 correlation, most large moves hit both names, and the diversification benefit stays modest.
What does a correlation of 0.54 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: DGII correlations · MDY correlations
