MDY vs PPLI: Correlation
How closely do SPDR S&P MidCap 400 ETF (MDY) and People Incorporated (PPLI) trade together? Their weekly returns over three years give a correlation of 0.56, which is moderate.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are MDY and PPLI?
Across a 3-year window, the weekly returns of MDY and PPLI correlate at 0.56, moderate. Little has changed lately, as the 1-year reading of 0.53 lands near the 3-year figure. Stretching to 5 years gives 0.54, with an annualized covariance of 296.9 %².
Among the 359 assets we track against MDY, PPLI ranks #237 by 3-year correlation. Over the last 12 months MDY came out ahead by 11.3 percentage points (+18.3% against +7.0%). Risk is not evenly split, since PPLI carries 1.9 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 PPLI: side by side
| MDY (SPDR S&P MidCap 400 ETF) | PPLI (People Incorporated) | |
|---|---|---|
| 1-year return | +18.3% | +7.0% |
| 5-year return | +47.5% | -63.8% |
| Volatility (ann.) | 16.5% | 32.1% |
| Beta vs S&P 500 | 0.91 | 0.98 |
| Max drawdown (3Y) | -24.0% | -33.4% |
| Market cap | – | $2.9B |
| P/E (trailing) | – | 6.6 |
| 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 | PPLI |
|---|---|---|
| 2022 | -13.3% | -66.0% |
| 2023 | +16.1% | +18.0% |
| 2024 | +13.6% | -17.6% |
| 2025 | +7.2% | +10.5% |
| 2026 | +16.4% | +0.6% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are MDY and PPLI good diversifiers for each other?
Somewhat, no more. With 0.56 correlation, most large moves hit both names, and the diversification benefit stays modest.
FAQ
What is the correlation between MDY and PPLI?
As of 2026-08-27, the correlation of weekly returns between MDY and PPLI is 0.56 over 3 years, 0.53 over 1 year and 0.54 over 5 years.
Is PPLI a good diversifier for MDY?
Somewhat, no more. With 0.56 correlation, most large moves hit both names, and the diversification benefit stays modest.
What does a correlation of 0.56 mean?
A reading of 0.56 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-ppli.json
Drop this badge in a README or notebook; it updates with the data:
[](https://www.pairbook.io/pair/mdy-vs-ppli/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: MDY correlations · PPLI correlations
