IWF vs MGK: 71% overlap
iShares Russell 1000 Growth ETF and Vanguard Mega Cap Growth ETF share 71.2% 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 1.3. Two funds that shared nothing would score 2.0; two identical funds score 1.0.
Top shared holdings
IWF and MGK hold 48 of the same securities. The ten contributing most to the overlap figure:
| Holding | in IWF | in MGK | Δ |
|---|---|---|---|
| NVDA | 15.1% | 13.2% | 1.9% |
| AAPL | 7.8% | 12.1% | 4.3% |
| GOOGL | 5.7% | 5.9% | 0.2% |
| GOOG | 4.7% | 4.6% | 0.0% |
| MSFT | 4.4% | 7.5% | 3.1% |
| AVGO | 5.7% | 4.3% | 1.4% |
| META | 3.4% | 4.1% | 0.7% |
| LLY | 2.9% | 3.4% | 0.5% |
| TSLA | 2.9% | 3.9% | 1.0% |
| AMD | 2.7% | 3.2% | 0.5% |
Where IWF and MGK 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 | IWF | MGK | Δ |
|---|---|---|---|
| Industrials | 8.5% | 2.6% | +5.9pp |
| Consumer Discretionary | 7.5% | 11.2% | −3.7pp |
| Information Technology | 55.0% | 58.6% | −3.6pp |
| Consumer Staples | 1.3% | 0.4% | +0.9pp |
| Real Estate | 0.4% | 1.2% | −0.8pp |
| Financials | 4.7% | 4.0% | +0.7pp |
| Health Care | 5.6% | 4.9% | +0.7pp |
| Energy | 0.5% | 0.0% | +0.5pp |
Δ is IWF minus MGK, 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
25.1% of IWF by weight, held in no part of MGK.
5.0% of MGK by weight, held in no part of IWF.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| IWF | MGK | |
|---|---|---|
| Top 10 holdings | 56.1% | 63.5% |
| Positions held | 370 | 57 |
| Cost per $10,000 held, per year | $19 | $5 |
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 IWF and MGK overlap?
IWF and MGK overlap 71.2% by portfolio weight — substantial duplication if you hold both. They share 48 holdings. The figure comes from current issuer holdings files (IWF as of 2026-07-23, MGK as of 2026-06-30).
How is the overlap between IWF and MGK calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If IWF holds a stock at 6% and MGK 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 IWF and MGK?
That depends on your goals — we state facts, not advice. At 71.2% overlap, most of what one fund holds, the other holds too. Expense ratios: IWF 0.19% versus MGK 0.05%.
What does IWF own that MGK doesn't?
IWF holds 370 positions and MGK holds 57; 321 of IWF's positions don't appear in MGK at all, and they are 25.1% of IWF by weight.
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Related comparisons
Sources: issuer holdings files, IWF as of 2026-07-23, MGK as of 2026-06-30. Weights are fractions of each fund. Diagnostics, not advice.