IEMG vs MDY: 0% overlap
iShares Core MSCI Emerging Markets ETF and SPDR S&P MidCap 400 ETF Trust share 0.4% of their portfolios by weight — computed as Σ min(wA, wB) over every holding both funds own.
You would hold two tickers and get the diversification of 2.0. Two funds that shared nothing would score 2.0; two identical funds score 1.0.
Top shared holdings
IEMG and MDY hold 14 of the same securities. The ten contributing most to the overlap figure:
| Holding | in IEMG | in MDY | Δ |
|---|---|---|---|
| MTN | 0.2% | 0.1% | 0.0% |
| VAL | 0.1% | 0.1% | 0.0% |
| SLM | 0.1% | 0.1% | 0.1% |
| PPC | 0.0% | 0.0% | 0.0% |
| MOH | 0.0% | 0.3% | 0.3% |
| NXST | 0.0% | 0.1% | 0.1% |
| TRU | 0.0% | 0.4% | 0.4% |
| CNH | 0.0% | 0.3% | 0.3% |
| OSK | 0.0% | 0.3% | 0.3% |
| SCI | 0.0% | 0.3% | 0.3% |
Where IEMG and MDY differ
Sector weights as a share of each fund, ordered by the size of the gap rather than the size of the sector — two funds that overlap heavily still usually diverge somewhere.
| Sector | IEMG | MDY | Δ |
|---|---|---|---|
| Information Technology | 39.8% | 13.8% | +26.0pp |
| Industrials | 7.7% | 25.4% | −17.6pp |
| Health Care | 3.1% | 9.7% | −6.5pp |
| Real Estate | 1.5% | 6.9% | −5.3pp |
| Communication Services | 5.4% | 1.5% | +3.9pp |
| Financials | 18.1% | 14.8% | +3.3pp |
| Consumer Discretionary | 8.5% | 10.2% | −1.7pp |
| Energy | 3.5% | 4.9% | −1.4pp |
Δ is IEMG minus MDY, in percentage points. Sector data is not published by every issuer, so “Unclassified” is a real category rather than a gap in the table.
What each fund holds alone
98.8% of IEMG by weight, held in no part of MDY.
96.0% of MDY by weight, held in no part of IEMG.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| IEMG | MDY | |
|---|---|---|
| Top 10 holdings | 33.6% | 7.6% |
| Positions held | 2,790 | 400 |
| Cost per $10,000 held, per year | $9 | $23 |
Cost is the expense ratio applied to $10,000; it excludes any brokerage commission, bid-ask spread or tax consequence. Figures are facts about the funds, not a suggestion about which to hold.
Frequently asked
How much do IEMG and MDY overlap?
IEMG and MDY overlap 0.4% by portfolio weight — largely distinct portfolios. They share 14 holdings. The figure comes from current issuer holdings files (IEMG as of 2026-07-23, MDY as of 2026-07-23).
How is the overlap between IEMG and MDY calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If IEMG holds a stock at 6% and MDY holds the same stock at 4%, 4% counts as shared. The result is bounded between 0% and 100%, and it is computed after looking through any fund-of-funds to the underlying holdings.
Is it redundant to hold both IEMG and MDY?
That depends on your goals — we state facts, not advice. At 0.4% overlap, each fund still contributes meaningfully distinct exposure.
What does IEMG own that MDY doesn't?
IEMG holds 2,790 positions and MDY holds 400; 2,775 of IEMG's positions don't appear in MDY at all, and they are 98.8% of IEMG by weight.
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Related comparisons
Sources: issuer holdings files, IEMG as of 2026-07-23, MDY as of 2026-07-23. Weights are fractions of each fund. Diagnostics, not advice.