IWF vs VO: 10% overlap
iShares Russell 1000 Growth ETF and Vanguard Mid-Cap ETF share 10.3% 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 1.9. Two funds that shared nothing would score 2.0; two identical funds score 1.0.
Top shared holdings
IWF and VO hold 104 of the same securities. The ten contributing most to the overlap figure:
| Holding | in IWF | in VO | Δ |
|---|---|---|---|
| WDC | 0.6% | 1.1% | 0.5% |
| VRT | 0.4% | 1.2% | 0.9% |
| HWM | 0.4% | 1.0% | 0.7% |
| PWR | 0.3% | 1.0% | 0.7% |
| FTNT | 0.3% | 0.5% | 0.2% |
| SNOW | 0.3% | 0.4% | 0.1% |
| NET | 0.3% | 0.8% | 0.5% |
| DDOG | 0.2% | 0.8% | 0.6% |
| SPG | 0.2% | 0.7% | 0.4% |
| HLT | 0.2% | 0.4% | 0.1% |
Where IWF and VO 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 | VO | Δ |
|---|---|---|---|
| Information Technology | 55.0% | 16.1% | +38.9pp |
| Communication Services | 15.7% | 2.8% | +12.9pp |
| Industrials | 8.5% | 19.6% | −11.1pp |
| Financials | 4.7% | 14.0% | −9.3pp |
| Utilities | 0.3% | 8.4% | −8.0pp |
| Energy | 0.5% | 7.3% | −6.8pp |
| Real Estate | 0.4% | 5.1% | −4.6pp |
| Materials | 0.3% | 4.3% | −4.1pp |
Δ is IWF minus VO, 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
89.7% of IWF by weight, held in no part of VO.
54.5% of VO 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 | VO | |
|---|---|---|
| Top 10 holdings | 56.1% | 9.5% |
| Positions held | 370 | 283 |
| Cost per $10,000 held, per year | $19 | $3 |
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 VO overlap?
IWF and VO overlap 10.3% by portfolio weight — largely distinct portfolios. They share 104 holdings. The figure comes from current issuer holdings files (IWF as of 2026-07-23, VO as of 2026-06-30).
How is the overlap between IWF and VO 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 VO 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 VO?
That depends on your goals — we state facts, not advice. At 10.3% overlap, each fund still contributes meaningfully distinct exposure.
What does IWF own that VO doesn't?
IWF holds 370 positions and VO holds 283; 265 of IWF's positions don't appear in VO at all, and they are 89.7% of IWF by weight.
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Related comparisons
Sources: issuer holdings files, IWF as of 2026-07-23, VO as of 2026-06-30. Weights are fractions of each fund. Diagnostics, not advice.