Data as of Sep 12, 2026. Both funds on the fields they both publish, from the same sources.
IBB vs IWB: how they differ
IBB and IWB hold 1% of their weight in the same names, and IBB returned more over the year.
iShares Biotechnology ETF and iShares Russell 1000 ETF.
What they hold in common
By the books each fund has filed, IBB and IWB hold 1% of their money in the same securities at the same weight.
| Holding | IBB | IWB |
|---|---|---|
| Amgen, Inc. | 7.84% | 0.28% |
| Gilead Sciences, Inc. | 6.85% | 0.23% |
| Vertex Pharmaceuticals, Inc. | 8.09% | 0.18% |
| Regeneron Pharmaceuticals, Inc. | 4.91% | 0.09% |
| Alnylam Pharmaceuticals, Inc. | 3.12% | 0.06% |
| Natera, Inc. | 2.89% | 0.05% |
| Revolution Medicines, Inc. | 2.78% | 0.05% |
| Biogen, Inc. | 2.47% | 0.05% |
| Illumina, Inc. | 2.07% | 0.04% |
| Moderna, Inc. | 1.99% | 0.04% |
| Insmed, Inc. | 1.79% | 0.03% |
| United Therapeutics Corp. | 1.74% | 0.03% |
| Only in IBB | Only in IWB |
|---|---|
| Argenx SE 3.76% | NVIDIA CORPORATION 6.73% |
| BeOne Medicines Ltd. 1.77% | APPLE INC. 6.03% |
| Roivant Sciences Ltd. 1.43% | MICROSOFT CORPORATION 4.00% |
| Ascendis Pharma A/S 1.29% | AMAZON.COM, INC. 3.33% |
| Genmab A/S 1.12% | ALPHABET INC. 3.00% |
| Cytokinetics, Inc. 0.79% | BROADCOM INC. 2.54% |
| Krystal Biotech, Inc. 0.75% | ALPHABET INC. 2.42% |
| Praxis Precision Medicines, Inc. 0.68% | MICRON TECHNOLOGY, INC. 1.88% |
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 | IWB iShares Russell 1000 ETF | |
|---|---|---|
| Where it sits | Core index fund | Core index fund |
| Issuer | iShares | iShares |
| What it is | Biotechnology | Russell 1000 |
| Total return, 1 year | +41.5% | +16.7% |
| S&P 500 over the same days | +17.5% | +17.5% |
| Gap to the S&P 500 | +24.0 pts | −0.8 pts |
| Expense ratio | 0.44% | 0.15% |
| Already in the S&P 500 | 35.6% | 91.9% |
| Holdings | 248 | 1024 |
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.
IWB in plain words
IWB is an index equity fund tracking the Russell 1000. Over the year to Sep 11, 2026 it returned +16.7% with distributions reinvested, against +17.5% for the S&P 500 and +23.0% for the Nasdaq-100. The prospectus expense ratio is 0.15% a year. By its holdings filed for Jun 30, 2026, 92% of the fund by weight is stocks the S&P 500 also holds, across 1024 positions, with the top ten at 33.5%.
Questions people ask
- Which returned more over the last year, IBB or IWB?
- In the year to Sep 12, 2026, with distributions reinvested, IBB returned +41.5% and IWB returned +16.7%, so IBB returned more. One year is one year; the longer windows are in the table.
- Which is cheaper, IBB or IWB?
- IBB charges 0.44% a year and IWB charges 0.15%, so IWB is cheaper. Fees come from each fund's prospectus.
- How much do IBB and IWB overlap with the S&P 500?
- By their latest filed holdings, 36% of IBB and 92% of IWB by weight is stocks the S&P 500 already holds. Between the two funds, 1% of their books are the same securities at the same weight.
Other comparisons
Where to next
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 IWB, data as of Sep 12, 2026. https://etfiq.com/compare/any/IBB-IWB Free to use with attribution; the underlying files are at Open data.
A comparison is not a recommendation. Standards and sources