Data as of Sep 13, 2026. Both funds on the fields they both publish, from the same sources.
IBB vs IWO: how they differ
IBB and IWO hold 15% of their weight in the same names, and IBB returned more over the year.
iShares Biotechnology ETF and iShares Russell 2000 Growth ETF.
What they hold in common
By the books each fund has filed, IBB and IWO hold 15% of their money in the same securities at the same weight.
| Holding | IBB | IWO |
|---|---|---|
| KRYSTAL BIOTECH | 0.66% | 0.59% |
| PROTAGONIST THERAPEUTICS | 0.66% | 0.59% |
| PRAXIS PRECISION MEDICINES | 0.65% | 0.56% |
| TWIST BIOSCIENCE | 0.56% | 0.54% |
| 10X GENOMICS CLASS A | 0.55% | 0.52% |
| SPYRE THERAPEUTICS INC | 0.51% | 0.43% |
| ALKERMES | 0.56% | 0.40% |
| KYMERA THERAPEUTICS | 0.62% | 0.40% |
| TRAVERE THERAPEUTICS | 0.45% | 0.40% |
| SCHOLAR ROCK HOLDING | 0.40% | 0.38% |
| XENON PHARMACEUTICALS | 0.40% | 0.38% |
| RHYTHM PHARMACEUTICALS | 0.50% | 0.37% |
| Only in IBB | Only in IWO |
|---|---|
| VERTEX PHARMACEUTICALS 7.94% | MOOG INC CLASS A 0.69% |
| AMGEN INC 7.85% | GLAUKOS 0.65% |
| GILEAD SCIENCES 7.44% | JFROG 0.64% |
| REGENERON PHARMACEUTICALS 5.92% | BRIGHTSPRING HEALTH SERVICES INC 0.62% |
| ARGENX SE ADR 3.78% | FIRSTCASH HOLDINGS INC 0.62% |
| MODERNA 3.67% | BRINKER INTERNATIONAL INC 0.61% |
| NATERA 3.30% | INTERDIGITAL INC 0.60% |
| REVOLUTION MEDICINES 2.87% | RYMAN HOSPITALITY PROPERTIES REIT 0.55% |
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 Sep 10, 2026.
| IBB iShares Biotechnology ETF | IWO iShares Russell 2000 Growth ETF | |
|---|---|---|
| Where it sits | Core index fund | Core index fund |
| Issuer | iShares | iShares |
| What it is | Biotechnology | Russell 2000 Growth |
| Total return, 1 year | +41.5% | +17.0% |
| S&P 500 over the same days | +17.5% | +17.5% |
| Gap to the S&P 500 | +24.0 pts | −0.5 pts |
| Expense ratio | 0.44% | 0.24% |
| Already in the S&P 500 | 35.6% | 0.0% |
| Holdings | 233 | 970 |
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 Sep 10, 2026, 36% of the fund by weight is stocks the S&P 500 also holds, across 233 positions, with the top ten at 47.5%. It sat 6.5% below its high of Aug 19, 2026 on Sep 11, 2026.
IWO in plain words
IWO is an index equity fund tracking the Russell 2000 Growth. Over the year to Sep 11, 2026 it returned +17.0% with distributions reinvested, against +17.5% for the S&P 500 and +23.0% for the Nasdaq-100. The prospectus expense ratio is 0.24% a year. By its holdings filed for Sep 10, 2026, 0% of the fund by weight is stocks the S&P 500 also holds, across 970 positions, with the top ten at 6.2%. It sat 7.1% below its high of Aug 14, 2026 on Sep 11, 2026.
Questions people ask
- Which returned more over the last year, IBB or IWO?
- In the year to Sep 13, 2026, with distributions reinvested, IBB returned +41.5% and IWO returned +17.0%, so IBB returned more. One year is one year; the longer windows are in the table.
- Which is cheaper, IBB or IWO?
- IBB charges 0.44% a year and IWO charges 0.24%, so IWO is cheaper. Fees come from each fund's prospectus.
- How much do IBB and IWO overlap with the S&P 500?
- By their latest filed holdings, 36% of IBB and 0% of IWO by weight is stocks the S&P 500 already holds. Between the two funds, 15% 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 IWO, data as of Sep 13, 2026. https://etfiq.com/compare/any/ibb-vs-iwo Free to use with attribution; the underlying files are at Open data.
A comparison is not a recommendation. Standards and sources