APG vs MDY: Correlation
How closely do APi Group Corporation (APG) and SPDR S&P MidCap 400 ETF (MDY) trade together? Their weekly returns over three years give a correlation of 0.66, which is strong.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are APG and MDY?
Over the past 3 years, APG and MDY moved with a correlation of 0.66, which is strong. The relationship has been stable: the 1-year correlation (0.62) sits close to the 3-year figure. Over 5 years the correlation is 0.74, and the annualized covariance of weekly returns is 297.3 %².
In APG's tracked universe of 12 assets, MDY sits right near the top at #1. Neither side won the trailing year by much: +13.5% against +18.3%. One caveat on sizing: APG is 1.6 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.
APG vs MDY: side by side
| APG (APi Group Corporation) | MDY (SPDR S&P MidCap 400 ETF) | |
|---|---|---|
| 1-year return | +13.5% | +18.3% |
| 5-year return | +165.2% | +47.5% |
| Volatility (ann.) | 27.2% | 16.5% |
| Beta vs S&P 500 | 1.14 | 0.91 |
| Max drawdown (3Y) | -22.2% | -24.0% |
| Market cap | $17.8B | – |
| P/E (trailing) | – | – |
| Dividend yield | 0.00% | 1.02% |
| Expense ratio | – | 0.23% |
| Assets under management | – | $26.5B |
| Sector / category | US Listed | ETF · US Small & Mid Cap |
MDY, State Street Investment Management's Mid-Cap Blend fund, carries $26.5B under management, 400 holdings, a 0.23% expense ratio, a 1.02% trailing dividend yield.
Year-by-year returns
| Year | APG | MDY |
|---|---|---|
| 2022 | -27.0% | -13.3% |
| 2023 | +83.9% | +16.1% |
| 2024 | +4.0% | +13.6% |
| 2025 | +59.5% | +7.2% |
| 2026 | +7.8% | +16.4% |
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 APG at a 0.44% weight, which makes a slice of this correlation mechanical rather than coincidental.
Are APG and MDY good diversifiers for each other?
To a limited degree. At 0.66 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 APG and MDY?
The APG/MDY correlation stands at 0.66 on a 3-year window (1 year: 0.62, 5 years: 0.74), computed from weekly returns as of 2026-08-27.
Is MDY a good diversifier for APG?
To a limited degree. At 0.66 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 0.66 mean?
On the −1 to +1 scale, 0.66 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.
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Related comparisons
Hubs: APG correlations · MDY correlations
