Data as of Sep 12, 2026. Both funds on the fields they both publish, from the same sources.
IWB vs MGK: how they differ
IWB and MGK hold 47% of their weight in the same names, and IWB returned more over the year.
iShares Russell 1000 ETF and Vanguard Mega Cap Growth Index Fund.
What they hold in common
By the books each fund has filed, IWB and MGK hold 47% of their money in the same securities at the same weight.
| Holding | IWB | MGK |
|---|---|---|
| NVIDIA CORPORATION | 6.73% | 13.29% |
| APPLE INC. | 6.03% | 12.19% |
| MICROSOFT CORPORATION | 4.00% | 7.52% |
| AMAZON.COM, INC. | 3.33% | 4.47% |
| ALPHABET INC. | 3.00% | 5.93% |
| BROADCOM INC. | 2.54% | 4.28% |
| ALPHABET INC. | 2.42% | 4.67% |
| META PLATFORMS, INC. | 1.79% | 4.08% |
| TESLA, INC. | 1.77% | 3.93% |
| ELI LILLY AND COMPANY | 1.38% | 3.41% |
| ADVANCED MICRO DEVICES, INC. | 1.36% | 3.20% |
| INTEL CORPORATION | 0.88% | 1.10% |
| Only in IWB | Only in MGK |
|---|---|
| MICRON TECHNOLOGY, INC. 1.88% | Seagate Technology Holdings PLC 0.51% |
| BERKSHIRE HATHAWAY INC. 1.34% | |
| JPMORGAN CHASE & CO. 1.26% | |
| JOHNSON & JOHNSON 0.88% | |
| EXXON MOBIL CORPORATION 0.82% | |
| WALMART INC. 0.72% | |
| CATERPILLAR INC. 0.70% | |
| CISCO SYSTEMS, INC. 0.67% |
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.
| IWB iShares Russell 1000 ETF | MGK Vanguard Mega Cap Growth Index Fund | |
|---|---|---|
| Where it sits | Core index fund | Core index fund |
| Issuer | iShares | Vanguard |
| What it is | Russell 1000 | Mega Cap Growth |
| Total return, 1 year | +16.7% | +14.9% |
| S&P 500 over the same days | +17.5% | +17.5% |
| Gap to the S&P 500 | −0.8 pts | −2.6 pts |
| Expense ratio | 0.15% | 0.07% |
| Already in the S&P 500 | 91.9% | 99.2% |
| Holdings | 1024 | 56 |
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%.
MGK in plain words
MGK is an index equity fund tracking the Mega Cap Growth. Over the year to Sep 11, 2026 it returned +14.9% with distributions reinvested, against +17.5% for the S&P 500 and +23.0% for the Nasdaq-100. The prospectus expense ratio is 0.07% a year. By its holdings filed for Jun 30, 2026, 99% of the fund by weight is stocks the S&P 500 also holds, across 56 positions, with the top ten at 63.8%.
Questions people ask
- Which returned more over the last year, IWB or MGK?
- In the year to Sep 12, 2026, with distributions reinvested, IWB returned +16.7% and MGK returned +14.9%, so IWB returned more. One year is one year; the longer windows are in the table.
- Which is cheaper, IWB or MGK?
- IWB charges 0.15% a year and MGK charges 0.07%, so MGK is cheaper. Fees come from each fund's prospectus.
- How much do IWB and MGK overlap with the S&P 500?
- By their latest filed holdings, 92% of IWB and 99% of MGK by weight is stocks the S&P 500 already holds. Between the two funds, 47% 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, IWB against MGK, data as of Sep 12, 2026. https://etfiq.com/compare/any/IWB-MGK Free to use with attribution; the underlying files are at Open data.
A comparison is not a recommendation. Standards and sources