Data as of Sep 13, 2026. Both funds on the fields they both publish, from the same sources.
IWC vs IWO: how they differ
IWC and IWO hold 11% of their weight in the same names, and IWC returned more over the year.
iShares Micro-Cap ETF and iShares Russell 2000 Growth ETF.
What they hold in common
By the books each fund has filed, IWC and IWO hold 11% of their money in the same securities at the same weight.
| Holding | IWC | IWO |
|---|---|---|
| CAREDX | 0.61% | 0.17% |
| SELLAS LIFE SCIENCES GROUP INC | 0.60% | 0.17% |
| PENGUIN SOLUTIONS INC | 0.58% | 0.16% |
| OUSTER | 0.52% | 0.14% |
| MBX BIOSCIENCES | 0.45% | 0.12% |
| NURIX THERAPEUTICS | 0.59% | 0.12% |
| INNODATA | 0.40% | 0.11% |
| USD CASH | 0.11% | 0.14% |
| BANDWIDTH CLASS A | 0.36% | 0.10% |
| BUTTERFLY NETWORK CLASS A | 0.35% | 0.10% |
| ETON PHARMACEUTCIALS INC | 0.36% | 0.10% |
| NUVATION BIO CLASS A | 0.37% | 0.10% |
| Only in IWC | Only in IWO |
|---|---|
| QCR HOLDINGS INC 0.40% | MOOG INC CLASS A 0.69% |
| STRIVE INC CLASS A 0.40% | GLAUKOS 0.65% |
| ELLINGTON FINANCIAL 0.38% | JFROG 0.64% |
| NORDIC AMERICAN TANKERS LTD 0.35% | BRIGHTSPRING HEALTH SERVICES INC 0.62% |
| PEOPLES BANCORP INC 0.34% | FIRSTCASH HOLDINGS INC 0.62% |
| HYPERLIQUID STRATEGIES INC 0.33% | BRINKER INTERNATIONAL INC 0.61% |
| ORCHID ISLAND CAPITAL INC 0.31% | INTERDIGITAL INC 0.60% |
| COMMUNITY TRUST BANCORP 0.30% | KRYSTAL BIOTECH 0.59% |
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.
| IWC iShares Micro-Cap ETF | IWO iShares Russell 2000 Growth ETF | |
|---|---|---|
| Where it sits | Core index fund | Core index fund |
| Issuer | iShares | iShares |
| What it is | Russell Microcap | Russell 2000 Growth |
| Total return, 1 year | +31.3% | +17.0% |
| S&P 500 over the same days | +17.5% | +17.5% |
| Gap to the S&P 500 | +13.8 pts | −0.5 pts |
| Expense ratio | not published | 0.24% |
| Already in the S&P 500 | 91.9% | 0.0% |
| Holdings | 1252 | 970 |
IWC in plain words
IWC is an index equity fund tracking the Russell Microcap. Over the year to Sep 11, 2026 it returned +31.3% with distributions reinvested, against +17.5% for the S&P 500 and +23.0% for the Nasdaq-100. By its holdings filed for Sep 10, 2026, 92% of the fund by weight is stocks the S&P 500 also holds, across 1252 positions, with the top ten at 5.1%. It sat 5.0% below its high of Aug 14, 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, IWC or IWO?
- In the year to Sep 13, 2026, with distributions reinvested, IWC returned +31.3% and IWO returned +17.0%, so IWC returned more. One year is one year; the longer windows are in the table.
- How much do IWC and IWO overlap with the S&P 500?
- By their latest filed holdings, 92% of IWC and 0% of IWO by weight is stocks the S&P 500 already holds. Between the two funds, 11% 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, IWC against IWO, data as of Sep 13, 2026. https://etfiq.com/compare/any/iwc-vs-iwo Free to use with attribution; the underlying files are at Open data.
A comparison is not a recommendation. Standards and sources