MDY vs PPG: Correlation
How closely do SPDR S&P MidCap 400 ETF (MDY) and PPG Industries (PPG) trade together? Their weekly returns over three years give a correlation of 0.69, which is strong.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are MDY and PPG?
Across a 3-year window, the weekly returns of MDY and PPG correlate at 0.69, strong. Recent behaviour matches the longer record: 0.70 over 1 year against 0.69 over 3. Stretching to 5 years gives 0.71, with an annualized covariance of 288.7 %².
Within MDY's tracked universe of 359 assets, PPG comes in at #71 by 3-year correlation. Over the last 12 months MDY came out ahead by 14.5 percentage points (+18.3% against +3.8%). Stability stands out here, with the rolling one-year correlation confined to 0.60 through 0.78. Note the risk asymmetry: PPG runs 1.5 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 PPG: side by side
| MDY (SPDR S&P MidCap 400 ETF) | PPG (PPG Industries) | |
|---|---|---|
| 1-year return | +18.3% | +3.8% |
| 5-year return | +47.5% | -22.0% |
| Volatility (ann.) | 16.5% | 25.5% |
| Beta vs S&P 500 | 0.91 | 0.90 |
| Max drawdown (3Y) | -24.0% | -37.4% |
| Market cap | – | $25.2B |
| P/E (trailing) | – | 16.4 |
| Dividend yield | 1.02% | 2.48% |
| Expense ratio | 0.23% | – |
| Assets under management | $26.5B | – |
| Sector / category | ETF · US Small & Mid Cap | Materials |
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 | PPG |
|---|---|---|
| 2022 | -13.3% | -25.7% |
| 2023 | +16.1% | +21.2% |
| 2024 | +13.6% | -18.5% |
| 2025 | +7.2% | -12.0% |
| 2026 | +16.4% | +12.8% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are MDY and PPG good diversifiers for each other?
Only partially. A correlation of 0.69 means MDY and PPG 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 PPG?
Using weekly returns as of 2026-08-27: 0.69 over 3 years, with 0.70 over the last year and 0.71 over 5 years.
Is PPG a good diversifier for MDY?
Only partially. A correlation of 0.69 means MDY and PPG share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
What does a correlation of 0.69 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.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/mdy-vs-ppg.json
Markdown for the live badge, attribution link included:
[](https://www.pairbook.io/pair/mdy-vs-ppg/)
Free with attribution; caching and terms are described in the API documentation.
Related comparisons
Hubs: MDY correlations · PPG correlations
