MDY vs STGW: Correlation
Measured on weekly returns over the past three years, SPDR S&P MidCap 400 ETF (MDY) and Stagwell Inc. (STGW) carry a correlation of 0.48, a moderate link.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are MDY and STGW?
On 3 years of weekly data the MDY/STGW correlation comes out at 0.48, moderate. The link has loosened recently: the 1-year correlation (0.15) runs below the 3-year figure (0.48). The 5-year figure is 0.52, and annualized covariance runs at 385.0 %².
Within MDY's tracked universe of 359 assets, STGW comes in at #318 by 3-year correlation. Their recent paths diverged sharply: over the last 12 months STGW outperformed by 40.8 percentage points (+18.3% for MDY against +59.1% for STGW). One caveat on sizing: STGW is 3.0 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.
MDY vs STGW: side by side
| MDY (SPDR S&P MidCap 400 ETF) | STGW (Stagwell Inc.) | |
|---|---|---|
| 1-year return | +18.3% | +59.1% |
| 5-year return | +47.5% | +30.4% |
| Volatility (ann.) | 16.5% | 49.1% |
| Beta vs S&P 500 | 0.91 | 1.28 |
| Max drawdown (3Y) | -24.0% | -48.6% |
| Market cap | – | $2.2B |
| P/E (trailing) | – | 148.0 |
| Dividend yield | 1.02% | 0.00% |
| Expense ratio | 0.23% | – |
| Assets under management | $26.5B | – |
| Sector / category | ETF · US Small & Mid Cap | US Listed |
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 | MDY | STGW |
|---|---|---|
| 2022 | -13.3% | -28.4% |
| 2023 | +16.1% | +6.8% |
| 2024 | +13.6% | -0.8% |
| 2025 | +7.2% | -25.7% |
| 2026 | +16.4% | +81.6% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are MDY and STGW good diversifiers for each other?
A fair diversifier. At 0.48, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
FAQ
What is the correlation between MDY and STGW?
Using weekly returns as of 2026-08-27: 0.48 over 3 years, with 0.15 over the last year and 0.52 over 5 years.
Is STGW a good diversifier for MDY?
A fair diversifier. At 0.48, enough of each asset's movement is its own that the pair has smoothed outcomes historically.
What does a correlation of 0.48 mean?
A reading of 0.48 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-stgw.json
Markdown for the live badge, attribution link included:
[](https://www.pairbook.io/pair/mdy-vs-stgw/)
No key needed, free to use. Full endpoint list in the API documentation.
Related comparisons
Hubs: MDY correlations · STGW correlations
