IR vs MDY: Correlation
How closely do Ingersoll Rand (IR) and SPDR S&P MidCap 400 ETF (MDY) trade together? Their weekly returns over three years give a correlation of 0.73, which is strong.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are IR and MDY?
On 3 years of weekly data the IR/MDY correlation comes out at 0.73, strong. The relationship has been stable: the 1-year correlation (0.69) sits close to the 3-year figure. The 5-year figure is 0.74, and annualized covariance runs at 357.2 %².
MDY is one of the assets that tracks IR most closely: it ranks #3 out of the 61 assets we track against IR. Their recent paths diverged sharply: over the last 12 months MDY outperformed by 20.3 percentage points (-2.0% for IR against +18.3% for MDY). On a rolling one-year basis the correlation drifted between 0.55 and 0.85, a moderate band. Risk is not evenly split, since IR 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.
IR vs MDY: side by side
| IR (Ingersoll Rand) | MDY (SPDR S&P MidCap 400 ETF) | |
|---|---|---|
| 1-year return | -2.0% | +18.3% |
| 5-year return | +49.2% | +47.5% |
| Volatility (ann.) | 29.8% | 16.5% |
| Beta vs S&P 500 | 1.17 | 0.91 |
| Max drawdown (3Y) | -36.6% | -24.0% |
| Market cap | $30.6B | – |
| P/E (trailing) | 32.6 | – |
| Dividend yield | 0.15% | 1.02% |
| Expense ratio | – | 0.23% |
| Assets under management | – | $26.5B |
| Sector / category | Industrials | 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 | IR | MDY |
|---|---|---|
| 2022 | -15.4% | -13.3% |
| 2023 | +48.2% | +16.1% |
| 2024 | +17.1% | +13.6% |
| 2025 | -12.3% | +7.2% |
| 2026 | -0.2% | +16.4% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are IR and MDY good diversifiers for each other?
To a limited degree. At 0.73 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 IR and MDY?
The IR/MDY correlation stands at 0.73 on a 3-year window (1 year: 0.69, 5 years: 0.74), computed from weekly returns as of 2026-08-27.
Is MDY a good diversifier for IR?
To a limited degree. At 0.73 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 0.73 mean?
A reading of 0.73 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: IR correlations · MDY correlations
