MDY vs PH: Correlation
How closely do SPDR S&P MidCap 400 ETF (MDY) and Parker Hannifin (PH) trade together? Their weekly returns over three years give a correlation of 0.72, which is strong.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are MDY and PH?
On 3 years of weekly data the MDY/PH correlation comes out at 0.72, strong. The link has loosened recently: the 1-year correlation (0.60) runs below the 3-year figure (0.72). The 5-year figure is 0.78, and annualized covariance runs at 315.6 %².
By 3-year correlation, PH places #49 of the 359 assets tracked against MDY. Over the last 12 months PH came out ahead by 14.5 percentage points (+18.3% against +32.8%). Across three years, the rolling one-year figure varied moderately, from 0.58 to 0.87. Note the risk asymmetry: PH runs 1.6 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.
MDY vs PH: side by side
| MDY (SPDR S&P MidCap 400 ETF) | PH (Parker Hannifin) | |
|---|---|---|
| 1-year return | +18.3% | +32.8% |
| 5-year return | +47.5% | +256.4% |
| Volatility (ann.) | 16.5% | 26.6% |
| Beta vs S&P 500 | 0.91 | 1.16 |
| Max drawdown (3Y) | -24.0% | -26.8% |
| Market cap | – | $127.5B |
| P/E (trailing) | – | 36.5 |
| Dividend yield | 1.02% | 0.71% |
| 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 | PH |
|---|---|---|
| 2022 | -13.3% | -6.9% |
| 2023 | +16.1% | +60.8% |
| 2024 | +13.6% | +39.6% |
| 2025 | +7.2% | +39.5% |
| 2026 | +16.4% | +15.5% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are MDY and PH good diversifiers for each other?
To a limited degree. At 0.72 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 PH?
As of 2026-08-27, the correlation of weekly returns between MDY and PH is 0.72 over 3 years, 0.60 over 1 year and 0.78 over 5 years.
Is PH a good diversifier for MDY?
To a limited degree. At 0.72 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 0.72 mean?
A reading of 0.72 sits on a scale from −1 (opposite moves) through 0 (unrelated) to +1 (identical moves). Correlation captures direction, not magnitude or performance.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/mdy-vs-ph.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/mdy-vs-ph/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: MDY correlations · PH correlations
