IEMG vs MDY: Correlation & Overlap
How closely do iShares Core MSCI Emerging Markets ETF (IEMG) and SPDR S&P MidCap 400 ETF (MDY) trade together? Their weekly returns over three years give a correlation of 0.61, which is strong. The two funds also share 0.4% of their portfolios by weight.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are IEMG and MDY?
Across a 3-year window, the weekly returns of IEMG and MDY correlate at 0.61, strong. Recent behaviour matches the longer record: 0.64 over 1 year against 0.61 over 3. Stretching to 5 years gives 0.61, with an annualized covariance of 175.1 %².
Within IEMG's tracked universe of 68 assets, MDY comes in at #34 by 3-year correlation. Their recent paths diverged sharply: over the last 12 months IEMG outperformed by 17.7 percentage points (+36.0% for IEMG against +18.3% for MDY). Across three years, the rolling one-year figure varied moderately, from 0.42 to 0.76.
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.
IEMG vs MDY: side by side
| IEMG (iShares Core MSCI Emerging Markets ETF) | MDY (SPDR S&P MidCap 400 ETF) | |
|---|---|---|
| 1-year return | +36.0% | +18.3% |
| 5-year return | +50.7% | +47.5% |
| Volatility (ann.) | 17.4% | 16.5% |
| Beta vs S&P 500 | 0.84 | 0.91 |
| Max drawdown (3Y) | -17.2% | -24.0% |
| Dividend yield | 2.31% | 1.02% |
| Expense ratio | 0.09% | 0.23% |
| Assets under management | $152.2B | $26.5B |
| Sector / category | ETF · International | ETF · US Small & Mid Cap |
IEMG is a Diversified Emerging Mkts fund from iShares: $152.2B under management, 1824 holdings, a 0.09% expense ratio, a 2.31% trailing dividend yield. 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.
Portfolio overlap between IEMG and MDY
The two portfolios are largely distinct. Weighing the shared positions, 0.4% of the two funds is identical, spread across 7 common holdings. That shared book is a large part of why the returns line up.
| Common holding | Weight in IEMG | Weight in MDY |
|---|---|---|
| VAL | 0.16% | 0.15% |
| MTN | 0.15% | 0.15% |
| SLM | 0.07% | 0.14% |
| PPC | 0.04% | 0.04% |
| MOH | 0.03% | 0.29% |
| NXST | 0.01% | 0.15% |
| TRU | 0.01% | 0.45% |
Largest positions held only by IEMG: 2330 (13.28%), 005930 (6.27%), 000660 (4.78%), 700 (2.49%), 9988 (1.77%). Only by MDY: TWLO (0.95%), P (0.94%), ILMN (0.93%), FTI (0.83%), ATI (0.80%).
Overlap = sum of the smaller of the two weights across common holdings, from issuer disclosures as of 2026-08-26. Top 7 common positions shown.
Year-by-year returns
| Year | IEMG | MDY |
|---|---|---|
| 2022 | -20.0% | -13.3% |
| 2023 | +11.5% | +16.1% |
| 2024 | +6.5% | +13.6% |
| 2025 | +32.6% | +7.2% |
| 2026 | +23.6% | +16.4% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are IEMG and MDY good diversifiers for each other?
Somewhat, no more. With 0.61 correlation, most large moves hit both names, and the diversification benefit stays modest.
FAQ
What is the correlation between IEMG and MDY?
The IEMG/MDY correlation stands at 0.61 on a 3-year window (1 year: 0.64, 5 years: 0.61), computed from weekly returns as of 2026-08-27.
Is MDY a good diversifier for IEMG?
Somewhat, no more. With 0.61 correlation, most large moves hit both names, and the diversification benefit stays modest.
How much do IEMG and MDY overlap?
0.4% by weight, across 7 common holdings, based on issuer-disclosed portfolios as of 2026-08-26.
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Hubs: IEMG correlations · MDY correlations
