EWJ vs MDY: Correlation & Overlap
Measured on weekly returns over the past three years, iShares MSCI Japan ETF (EWJ) and SPDR S&P MidCap 400 ETF (MDY) carry a correlation of 0.65, a strong link. By holdings, the two funds overlap 0% by weight.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are EWJ and MDY?
On 3 years of weekly data the EWJ/MDY correlation comes out at 0.65, strong. Recent behaviour matches the longer record: 0.67 over 1 year against 0.65 over 3. The 5-year figure is 0.68, and annualized covariance runs at 210.2 %².
Among the 70 assets we track against EWJ, MDY ranks #31 by 3-year correlation. The trailing year gives EWJ the advantage: +27.1% versus +18.3%, a 8.8-point spread. The rolling one-year correlation stayed in a tight band between 0.57 and 0.75 over the past three years, which points to a structural rather than episodic relationship.
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.
EWJ vs MDY: side by side
| EWJ (iShares MSCI Japan ETF) | MDY (SPDR S&P MidCap 400 ETF) | |
|---|---|---|
| 1-year return | +27.1% | +18.3% |
| 5-year return | +58.6% | +47.5% |
| Volatility (ann.) | 19.6% | 16.5% |
| Beta vs S&P 500 | 0.94 | 0.91 |
| Max drawdown (3Y) | -14.7% | -24.0% |
| Dividend yield | 3.86% | 1.02% |
| Expense ratio | 0.49% | 0.23% |
| Assets under management | $21.8B | $26.5B |
| Sector / category | ETF · International | ETF · US Small & Mid Cap |
On the fund side, EWJ sits in the Japan Stock category at iShares, with $21.8B under management, 168 holdings, a 0.49% expense ratio, a 3.86% 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 EWJ and MDY
The two portfolios are largely distinct: 0% of the funds' weight sits in the same underlying holdings (0 common positions). Correlation tells you they move together; overlap tells you why.
Largest positions held only by EWJ: 8306 (4.56%), 7203 (3.47%), 6857 (3.12%), 8035 (2.97%), 8316 (2.92%). 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.
Year-by-year returns
| Year | EWJ | MDY |
|---|---|---|
| 2022 | -17.7% | -13.3% |
| 2023 | +20.3% | +16.1% |
| 2024 | +7.0% | +13.6% |
| 2025 | +25.8% | +7.2% |
| 2026 | +19.3% | +16.4% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are EWJ and MDY good diversifiers for each other?
To a limited degree. At 0.65 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 EWJ and MDY?
The EWJ/MDY correlation stands at 0.65 on a 3-year window (1 year: 0.67, 5 years: 0.68), computed from weekly returns as of 2026-08-27.
Is MDY a good diversifier for EWJ?
To a limited degree. At 0.65 the two still catch most of the same waves, so the pair smooths returns a little without insulating either from a shared selloff.
How much do EWJ and MDY overlap?
0% by weight, across 0 common holdings, based on issuer-disclosed portfolios as of 2026-08-26.
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Related comparisons
Hubs: EWJ correlations · MDY correlations
