IEMG vs VOO: Correlation & Overlap
iShares Core MSCI Emerging Markets ETF (IEMG) and Vanguard S&P 500 ETF (VOO) show a strong relationship: their 3-year correlation of weekly returns is 0.70. Looking through to holdings, 0.1% of the two portfolios is the same by weight.
Data as of 2026-08-27 · refreshed every trading day · weekly returns · methodology
How correlated are IEMG and VOO?
Across a 3-year window, the weekly returns of IEMG and VOO correlate at 0.70, strong. Little has changed lately, as the 1-year reading of 0.73 lands near the 3-year figure. Stretching to 5 years gives 0.66, with an annualized covariance of 174.6 %².
Within IEMG's tracked universe of 68 assets, VOO comes in at #20 by 3-year correlation. Correlation aside, the last 12 months split them widely, with IEMG ahead by 15.4 points (+36.0% versus +20.6%). The rolling one-year correlation stayed in a tight band between 0.57 and 0.78 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.
IEMG vs VOO: side by side
| IEMG (iShares Core MSCI Emerging Markets ETF) | VOO (Vanguard S&P 500 ETF) | |
|---|---|---|
| 1-year return | +36.0% | +20.6% |
| 5-year return | +50.7% | +83.0% |
| Volatility (ann.) | 17.4% | 14.4% |
| Beta vs S&P 500 | 0.84 | 0.99 |
| Max drawdown (3Y) | -17.2% | -18.7% |
| Dividend yield | 2.31% | 1.07% |
| Expense ratio | 0.09% | 0.03% |
| Assets under management | $152.2B | $1,686.9B |
| Sector / category | ETF · International | ETF · US Large 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. VOO, Vanguard's Large Blend fund, carries $1,686.9B under management, 503 holdings, a 0.03% expense ratio, a 1.07% trailing dividend yield.
Portfolio overlap between IEMG and VOO
The two portfolios are largely distinct. Weighing the shared positions, 0.1% 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 VOO |
|---|---|---|
| HAL | 0.06% | 0.04% |
| BDX | 0.02% | 0.07% |
| TEL | 0.01% | 0.09% |
| ECL | 0.01% | 0.11% |
| LULU | 0.01% | 0.02% |
| SRE | 0.01% | 0.09% |
| CCL | 0.01% | 0.06% |
Largest positions held only by IEMG: 2330 (13.28%), 005930 (6.27%), 000660 (4.78%), 700 (2.49%), 9988 (1.77%). Only by VOO: NVDA (7.56%), AAPL (7.05%), MSFT (5.37%), AMZN (4.13%), GOOGL (3.25%).
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 | VOO |
|---|---|---|
| 2022 | -20.0% | -18.2% |
| 2023 | +11.5% | +26.3% |
| 2024 | +6.5% | +25.0% |
| 2025 | +32.6% | +17.8% |
| 2026 | +23.6% | +13.7% |
Calendar-year price returns; the current year is year-to-date as of the data date above.
Are IEMG and VOO good diversifiers for each other?
Only partially. A correlation of 0.70 means IEMG and VOO share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
FAQ
What is the correlation between IEMG and VOO?
Using weekly returns as of 2026-08-27: 0.70 over 3 years, with 0.73 over the last year and 0.66 over 5 years.
Is VOO a good diversifier for IEMG?
Only partially. A correlation of 0.70 means IEMG and VOO share most of their swings. Pairing them dampens volatility somewhat, but it will not protect against a common drawdown.
How much do IEMG and VOO overlap?
Per the issuers' own portfolio disclosures (2026-08-26), the overlap is 0.1% by weight over 7 common positions.
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