Data as of Sep 12, 2026. Both funds on the fields they both publish, from the same sources.
IBB vs VXF: how they differ
IBB and VXF hold 8% of their weight in the same names, and IBB returned more over the year.
iShares Biotechnology ETF and Vanguard Extended Market Index Fund.
What they hold in common
By the books each fund has filed, IBB and VXF hold 8% of their money in the same securities at the same weight.
| Holding | IBB | VXF |
|---|---|---|
| Alnylam Pharmaceuticals, Inc. | 3.12% | 0.47% |
| Natera, Inc. | 2.89% | 0.46% |
| Revolution Medicines, Inc. | 2.78% | 0.44% |
| Illumina, Inc. | 2.07% | 0.31% |
| Insmed, Inc. | 1.79% | 0.27% |
| United Therapeutics Corp. | 1.74% | 0.27% |
| Neurocrine Biosciences, Inc. | 1.30% | 0.20% |
| Exelixis, Inc. | 1.03% | 0.16% |
| Ionis Pharmaceuticals, Inc. | 1.00% | 0.15% |
| Bridgebio Pharma, Inc. | 0.98% | 0.15% |
| Medpace Holdings, Inc. | 0.95% | 0.14% |
| Cytokinetics, Inc. | 0.79% | 0.14% |
| Only in IBB | Only in VXF |
|---|---|
| Vertex Pharmaceuticals, Inc. 8.09% | Space Exploration Technologies Corp 1.19% |
| Amgen, Inc. 7.84% | Snowflake Inc 1.03% |
| Gilead Sciences, Inc. 6.85% | Bloom Energy Corp 0.93% |
| Regeneron Pharmaceuticals, Inc. 4.91% | Cloudflare Inc 0.92% |
| Argenx SE 3.76% | Astera Labs Inc 0.76% |
| Biogen, Inc. 2.47% | Rocket Lab Corp 0.61% |
| Moderna, Inc. 1.99% | Cheniere Energy Inc 0.59% |
| BeOne Medicines Ltd. 1.77% | Ferguson Enterprises Inc 0.54% |
Weight overlap is an ETFIQ calculation: for every security both funds hold, the smaller of the two weights, summed. Above 50%, holding both is close to holding one of them twice. Holdings dated Jun 30, 2026.
| IBB iShares Biotechnology ETF | VXF Vanguard Extended Market Index Fund | |
|---|---|---|
| Where it sits | Core index fund | Core index fund |
| Issuer | iShares | Vanguard |
| What it is | Biotechnology | Extended Market |
| Total return, 1 year | +41.5% | +14.1% |
| S&P 500 over the same days | +17.5% | +17.5% |
| Gap to the S&P 500 | +24.0 pts | −3.4 pts |
| Expense ratio | 0.44% | 0.05% |
| Already in the S&P 500 | 35.6% | 0.0% |
| Holdings | 248 | 3365 |
IBB in plain words
IBB is an index equity fund tracking the Biotechnology. Over the year to Sep 11, 2026 it returned +41.5% with distributions reinvested, against +17.5% for the S&P 500 and +23.0% for the Nasdaq-100. The prospectus expense ratio is 0.44% a year. By its holdings filed for Jun 30, 2026, 36% of the fund by weight is stocks the S&P 500 also holds, across 248 positions, with the top ten at 44.8%. It sat 6.5% below its high of Aug 19, 2026 on Sep 11, 2026.
VXF in plain words
VXF is an index equity fund tracking the Extended Market. Over the year to Sep 11, 2026 it returned +14.1% with distributions reinvested, against +17.5% for the S&P 500 and +23.0% for the Nasdaq-100. The prospectus expense ratio is 0.05% a year. By its holdings filed for Jun 30, 2026, 0% of the fund by weight is stocks the S&P 500 also holds, across 3365 positions, with the top ten at 7.6%. It sat 5.1% below its high of Aug 14, 2026 on Sep 11, 2026.
Questions people ask
- Which returned more over the last year, IBB or VXF?
- In the year to Sep 12, 2026, with distributions reinvested, IBB returned +41.5% and VXF returned +14.1%, so IBB returned more. One year is one year; the longer windows are in the table.
- Which is cheaper, IBB or VXF?
- IBB charges 0.44% a year and VXF charges 0.05%, so VXF is cheaper. Fees come from each fund's prospectus.
- How much do IBB and VXF overlap with the S&P 500?
- By their latest filed holdings, 36% of IBB and 0% of VXF by weight is stocks the S&P 500 already holds. Between the two funds, 8% of their books are the same securities at the same weight.
Other comparisons
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Where these figures came from
ETFIQ links to the documents behind every figure. It is not affiliated with any issuer, and a link is not an endorsement.
Cite this page. ETFIQ, IBB against VXF, data as of Sep 12, 2026. https://etfiq.com/compare/any/IBB-VXF Free to use with attribution; the underlying files are at Open data.
A comparison is not a recommendation. Standards and sources