MDY vs MTX: Correlation
How closely do SPDR S&P MidCap 400 ETF (MDY) and Minerals Technologies Inc. (MTX) trade together? Their weekly returns over three years give a correlation of 0.65, which is strong.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are MDY and MTX?
Over the past 3 years, MDY and MTX moved with a correlation of 0.65, which is strong. Lately the two have drifted apart, with the 1-year correlation at 0.53 versus 0.65 over 3 years. Over 5 years the correlation is 0.67, and the annualized covariance of weekly returns is 325.7 %².
Within MDY's tracked universe of 359 assets, MTX comes in at #114 by 3-year correlation. The trailing year gives MDY the advantage: +18.3% versus +12.0%, a 6.3-point spread. Risk is not evenly split, since MTX 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.
MDY vs MTX: side by side
| MDY (SPDR S&P MidCap 400 ETF) | MTX (Minerals Technologies Inc.) | |
|---|---|---|
| 1-year return | +18.3% | +12.0% |
| 5-year return | +47.5% | -6.2% |
| Volatility (ann.) | 16.5% | 30.4% |
| Beta vs S&P 500 | 0.91 | 0.90 |
| Max drawdown (3Y) | -24.0% | -42.5% |
| Market cap | – | $2.3B |
| P/E (trailing) | – | – |
| Dividend yield | 1.02% | 0.65% |
| 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 | MTX |
|---|---|---|
| 2022 | -13.3% | -16.7% |
| 2023 | +16.1% | +18.0% |
| 2024 | +13.6% | +7.4% |
| 2025 | +7.2% | -19.4% |
| 2026 | +16.4% | +19.2% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are MDY and MTX good diversifiers for each other?
Only partially. A correlation of 0.65 means MDY and MTX 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 MTX?
As of 2026-08-27, the correlation of weekly returns between MDY and MTX is 0.65 over 3 years, 0.53 over 1 year and 0.67 over 5 years.
Is MTX a good diversifier for MDY?
Only partially. A correlation of 0.65 means MDY and MTX share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
What does a correlation of 0.65 mean?
On the −1 to +1 scale, 0.65 describes how much the two returns move together: +1 is lockstep, 0 is independence, negative values mean opposite directions. It says nothing about which performed better.
Use this data
$ curl https://www.pairbook.io/api/v1/pairs/mdy-vs-mtx.json
Embed this badge (it refreshes with the data), with attribution:
[](https://www.pairbook.io/pair/mdy-vs-mtx/)
The core API is free. Terms and every endpoint in the API documentation.
Related comparisons
Hubs: MDY correlations · MTX correlations
