IWM vs VB Overlap
IWM is an equity ETF from IShares, while VB is a small-cap U.S. equity ETF from Vanguard. IWM and VB show meaningful overlap, with an estimated weighted overlap of 27.91%. They share 686 holdings in the loaded dataset, led by BE, CRDO, and FN.
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Quick Answer
IWM is an equity ETF from IShares, while VB is a small-cap U.S. equity ETF from Vanguard. IWM and VB show meaningful overlap, with an estimated weighted overlap of 27.91%. They share 686 holdings in the loaded dataset, led by BE, CRDO, and FN.
- 27.91% weighted overlap across 686 shared holdings.
- The top three shared holdings explain 3.3% of the measured overlap.
- IWM and VB are closer in breadth than a broad-vs-niche ETF pair.
- The overlap is mostly explained by the top shared positions rather than sector labels alone.
- Holding both may add less diversification than the fund names imply.
Data Freshness
- IWM holdings
- Mar 12, 2026
- VB holdings
- Mar 12, 2026
- Overlap computed
- Mar 15, 2026
- Data source
- Financial Modeling Prep
Review the methodology for the overlap formula and refresh policy.
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About These ETFs
What Stands Out In This Comparison
What This Means
IWM is an equity ETF from IShares, while VB is a small-cap U.S. equity ETF from Vanguard. IWM and VB overlap enough to matter, but they still bring different exposures to a portfolio. The overlap is concentrated in holdings such as BE, CRDO, and FN, which explains why the score lands at 27.91%.
How They Differ
IWM is an equity ETF from IShares, while VB is a small-cap U.S. equity ETF from Vanguard. Neither fund clearly dominates on breadth, so the practical difference is more about weighting, index construction, and cost. VB has the lower expense ratio, while IWM charges more for its exposure.
What Drives The Overlap
The overlap is driven by a relatively small set of large shared positions. The top three shared holdings account for 3.3% of the score, which means the result is heavily influenced by the biggest common weights rather than a long tail of tiny positions.
When One May Fit Better
Because IWM and VB are closer in breadth, the better fit usually comes down to index methodology, issuer preference, and cost. VB has the lower expense ratio, while IWM charges more for its exposure.
Overlap Driver Snapshot
Concentration
The top three shared holdings explain 3.3% of the full overlap score.
That helps show whether the score comes from a handful of giant shared positions or from a broader mix of common holdings.
Shared Sector Tilt
Sector tags are not consistently available for the biggest shared positions in this dataset, so this comparison leans more on the specific holdings than on sector labels.
Top Shared Holdings
These are the holdings contributing the most to the overlap score between IWM and VB.
| Holding | Name | IWM Wt. | VB Wt. | Overlap |
|---|---|---|---|---|
| BE | BLOOM ENERGY CLASS A CORP | 1.14% | 0.43% | 0.43% |
| CRDO | CREDO TECHNOLOGY GROUP HOLDING LTD | 0.58% | 0.26% | 0.26% |
| FN | FABRINET | 0.66% | 0.23% | 0.23% |
| KTOS | KRATOS DEFENSE AND SECURITY SOLUTI | 0.54% | 0.23% | 0.23% |
| NXT | NEXTPOWER INC CLASS A | 0.56% | 0.22% | 0.22% |
| SATS | ECHOSTAR CORP CLASS A | 0.50% | 0.20% | 0.20% |
| HL | HECLA MINING | 0.47% | 0.19% | 0.19% |
| GH | GUARDANT HEALTH INC | 0.37% | 0.18% | 0.18% |
| BBIO | BRIDGEBIO PHARMA INC | 0.40% | 0.18% | 0.18% |
| IONQ | IONQ INC | 0.40% | 0.17% | 0.17% |
Why These ETFs Overlap
IWM is an equity ETF from IShares, while VB is a small-cap U.S. equity ETF from Vanguard. The overlap exists because both funds allocate meaningful weight to the same holdings. In this dataset, the biggest shared drivers are BE, CRDO, and FN, which appear in both portfolios and push the overlap score higher.
Holding both IWM and VB can still be reasonable, but you should expect some duplication. The decision comes down to whether the non-overlapping parts of each ETF are important enough for your strategy.
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Frequently Asked Questions About IWM and VB
What is the overlap between IWM and VB?+
How many holdings do IWM and VB share?+
Is the IWM and VB overlap high?+
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Which ETF is broader, IWM or VB?+
How Overlap Is Calculated
A straightforward approach used by portfolio analysts.
For every stock that appears in both ETFs, we take the smaller of the two weights. Adding up all those minimums gives the total overlap percentage. A score of 100% means the two ETFs hold the exact same stocks in the same proportions.
Want the full explanation? Read the methodology page.