MDY vs SPXC: Correlation
How closely do SPDR S&P MidCap 400 ETF (MDY) and SPX Technologies, Inc. (SPXC) trade together? Their weekly returns over three years give a correlation of 0.61, which is strong.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are MDY and SPXC?
Across a 3-year window, the weekly returns of MDY and SPXC correlate at 0.61, strong. The link has loosened recently: the 1-year correlation (0.43) runs below the 3-year figure (0.61). Stretching to 5 years gives 0.63, with an annualized covariance of 340.2 %².
By 3-year correlation, SPXC places #168 of the 359 assets tracked against MDY. On 12-month performance MDY holds a 11.6-point edge, +18.3% against +6.7%. Note the risk asymmetry: SPXC runs 2.0 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 SPXC: side by side
| MDY (SPDR S&P MidCap 400 ETF) | SPXC (SPX Technologies, Inc.) | |
|---|---|---|
| 1-year return | +18.3% | +6.7% |
| 5-year return | +47.5% | +226.0% |
| Volatility (ann.) | 16.5% | 33.7% |
| Beta vs S&P 500 | 0.91 | 1.20 |
| Max drawdown (3Y) | -24.0% | -33.5% |
| Market cap | – | $10.3B |
| P/E (trailing) | – | 36.1 |
| Dividend yield | 1.02% | 0.00% |
| Expense ratio | 0.23% | – |
| Assets under management | $26.5B | – |
| Sector / category | ETF · US Small & Mid Cap | US Listed |
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 | SPXC |
|---|---|---|
| 2022 | -13.3% | +10.0% |
| 2023 | +16.1% | +53.9% |
| 2024 | +13.6% | +44.1% |
| 2025 | +7.2% | +37.5% |
| 2026 | +16.4% | +2.6% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Fund exposure
SPXC represents 0.28% of MDY's portfolio, so part of any move in MDY is SPXC itself, and the correlation between them is partly mechanical.
Are MDY and SPXC good diversifiers for each other?
To a limited degree. At 0.61 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 SPXC?
Using weekly returns as of 2026-08-27: 0.61 over 3 years, with 0.43 over the last year and 0.63 over 5 years.
Is SPXC a good diversifier for MDY?
To a limited degree. At 0.61 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 0.61 mean?
A reading of 0.61 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: MDY correlations · SPXC correlations
