MDY vs R: Correlation
SPDR S&P MidCap 400 ETF (MDY) and Ryder System, Inc. (R) show a strong relationship: their 3-year correlation of weekly returns is 0.65.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are MDY and R?
Across a 3-year window, the weekly returns of MDY and R correlate at 0.65, strong. The past 12 months show a weaker link (0.50) than the 3-year average (0.65). Stretching to 5 years gives 0.61, with an annualized covariance of 332.3 %².
Among the 359 assets we track against MDY, R ranks #115 by 3-year correlation. Correlation aside, the last 12 months split them widely, with R ahead by 16.6 points (+18.3% versus +34.9%). One caveat on sizing: R is 1.9 times as volatile as the other leg, so an equal-dollar split is far from equal-risk.
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 R: side by side
| MDY (SPDR S&P MidCap 400 ETF) | R (Ryder System, Inc.) | |
|---|---|---|
| 1-year return | +18.3% | +34.9% |
| 5-year return | +47.5% | +245.8% |
| Volatility (ann.) | 16.5% | 31.1% |
| Beta vs S&P 500 | 0.91 | 1.09 |
| Max drawdown (3Y) | -24.0% | -23.9% |
| Market cap | – | $9.5B |
| P/E (trailing) | – | 20.3 |
| Dividend yield | 1.02% | 1.46% |
| Expense ratio | 0.23% | – |
| Assets under management | $26.5B | – |
| Sector / category | ETF · US Small & Mid Cap | US Listed |
MDY is a Mid-Cap Blend fund from State Street Investment Management: $26.5B under management, 400 holdings, a 0.23% expense ratio, a 1.02% trailing dividend yield.
Year-by-year returns
| Year | MDY | R |
|---|---|---|
| 2022 | -13.3% | +4.4% |
| 2023 | +16.1% | +41.6% |
| 2024 | +13.6% | +39.5% |
| 2025 | +7.2% | +24.5% |
| 2026 | +16.4% | +31.2% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Fund exposure
Keep in mind that MDY holds R at a 0.26% weight, which makes a slice of this correlation mechanical rather than coincidental.
Are MDY and R good diversifiers for each other?
Somewhat, no more. With 0.65 correlation, most large moves hit both names, and the diversification benefit stays modest.
FAQ
What is the correlation between MDY and R?
The MDY/R correlation stands at 0.65 on a 3-year window (1 year: 0.50, 5 years: 0.61), computed from weekly returns as of 2026-08-27.
Is R a good diversifier for MDY?
Somewhat, no more. With 0.65 correlation, most large moves hit both names, and the diversification benefit stays modest.
What does a correlation of 0.65 mean?
A reading of 0.65 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-r.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/mdy-vs-r/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: MDY correlations · R correlations
