IWM vs VTIAX: 2% overlap
iShares Russell 2000 ETF and Vanguard Total International Stock Index Admiral share 1.6% 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
IWM and VTIAX hold 102 of the same securities. The ten contributing most to the overlap figure:
| Holding | in IWM | in VTIAX | Δ |
|---|---|---|---|
| AIR | 0.2% | 0.3% | 0.1% |
| CASH | 0.2% | 2.4% | 2.3% |
| CNR | 0.1% | 0.1% | 0.0% |
| MC | 0.1% | 0.3% | 0.2% |
| ORA | 0.2% | 0.1% | 0.1% |
| UCB | 0.1% | 0.1% | 0.0% |
| MTX | 0.1% | 0.0% | 0.0% |
| ENR | 0.0% | 0.3% | 0.3% |
| NN | 0.0% | 0.1% | 0.0% |
| ACA | 0.2% | 0.0% | 0.2% |
Where IWM and VTIAX 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 | IWM | VTIAX | Δ |
|---|---|---|---|
| Health Care | 19.9% | 5.3% | +14.6pp |
| Unclassified | 0.0% | 9.1% | −9.1pp |
| Information Technology | 12.8% | 20.9% | −8.1pp |
| Real Estate | 5.9% | 1.9% | +4.0pp |
| Energy | 6.1% | 3.0% | +3.1pp |
| Consumer Staples | 2.2% | 4.9% | −2.7pp |
| Cash and/or Derivatives | 0.2% | 2.5% | −2.3pp |
| Consumer Discretionary | 9.4% | 7.5% | +2.0pp |
Δ is IWM minus VTIAX, 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
93.8% of IWM by weight, held in no part of VTIAX.
95.0% of VTIAX by weight, held in no part of IWM.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| IWM | VTIAX | |
|---|---|---|
| Top 10 holdings | 3.3% | 16.3% |
| Positions held | 1,967 | 8,453 |
| Cost per $10,000 held, per year | $19 | $9 |
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 IWM and VTIAX overlap?
IWM and VTIAX overlap 1.6% by portfolio weight — largely distinct portfolios. They share 102 holdings. The figure comes from current issuer holdings files (IWM as of 2026-07-23, VTIAX as of 2026-06-30).
How is the overlap between IWM and VTIAX calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If IWM holds a stock at 6% and VTIAX 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 IWM and VTIAX?
That depends on your goals — we state facts, not advice. At 1.6% overlap, each fund still contributes meaningfully distinct exposure.
What does IWM own that VTIAX doesn't?
IWM holds 1,967 positions and VTIAX holds 8,453; 1,864 of IWM's positions don't appear in VTIAX at all, and they are 93.8% of IWM by weight.
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Related comparisons
Sources: issuer holdings files, IWM as of 2026-07-23, VTIAX as of 2026-06-30. Weights are fractions of each fund. Diagnostics, not advice.