Data as of Sep 13, 2026. Both funds on the fields they both publish, from the same sources.
IWF vs MDY: how they differ
IWF and MDY hold 0% of their weight in the same names, and MDY returned more over the year.
iShares Russell 1000 Growth ETF and SPDR S&P MidCap 400 ETF Trust.
What they hold in common
By the books each fund has filed, IWF and MDY hold 0% of their money in the same securities at the same weight.
| Only in IWF | Only in MDY |
|---|---|
| NVIDIA 15.46% | Twilio Inc. Class A 1.00% |
| APPLE 7.77% | Illumina Inc. 0.86% |
| ALPHABET CLASS A 5.88% | TechnipFMC plc 0.86% |
| MICROSOFT 5.55% | Everpure Inc. Class A 0.84% |
| BROADCOM INC 5.10% | Okta Inc. Class A 0.81% |
| ALPHABET CLASS C 4.77% | U.S. Dollar 0.80% |
| META PLATFORMS CLASS A 3.52% | ATI Inc 0.77% |
| MICRON TECHNOLOGY 3.35% | nVent Electric plc 0.71% |
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.
| IWF iShares Russell 1000 Growth ETF | MDY SPDR S&P MidCap 400 ETF Trust | |
|---|---|---|
| Where it sits | Core index fund | Core index fund |
| Issuer | iShares | State Street |
| What it is | Russell 1000 growth | S&P MidCap 400 |
| Total return, 1 year | +7.0% | +13.0% |
| S&P 500 over the same days | +17.5% | +17.5% |
| Gap to the S&P 500 | −10.5 pts | −4.5 pts |
| Expense ratio | 0.18% | 0.23% |
| Already in the S&P 500 | 93.6% | 0.0% |
| Holdings | 315 | 401 |
IWF in plain words
IWF is an index equity fund tracking the Russell 1000 growth. Over the year to Sep 11, 2026 it returned +7.0% with distributions reinvested, against +17.5% for the S&P 500 and +23.0% for the Nasdaq-100. The prospectus expense ratio is 0.18% a year. By its holdings filed for Sep 10, 2026, 94% of the fund by weight is stocks the S&P 500 also holds, across 315 positions, with the top ten at 57.3%. It sat 5.0% below its high of Jun 1, 2026 on Sep 11, 2026.
MDY in plain words
MDY is an index equity fund tracking the S&P MidCap 400. Over the year to Sep 11, 2026 it returned +13.0% with distributions reinvested, against +17.5% for the S&P 500 and +23.0% for the Nasdaq-100. The prospectus expense ratio is 0.23% 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 401 positions, with the top ten at 7.9%. It sat 5.3% below its high of Aug 14, 2026 on Sep 11, 2026.
Questions people ask
- Which returned more over the last year, IWF or MDY?
- In the year to Sep 13, 2026, with distributions reinvested, IWF returned +7.0% and MDY returned +13.0%, so MDY returned more. One year is one year; the longer windows are in the table.
- Which is cheaper, IWF or MDY?
- IWF charges 0.18% a year and MDY charges 0.23%, so IWF is cheaper. Fees come from each fund's prospectus.
- How much do IWF and MDY overlap with the S&P 500?
- By their latest filed holdings, 94% of IWF and 0% of MDY by weight is stocks the S&P 500 already holds. Between the two funds, 0% of their books are the same securities at the same weight.
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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, IWF against MDY, data as of Sep 13, 2026. https://etfiq.com/compare/any/iwf-vs-mdy Free to use with attribution; the underlying files are at Open data.
A comparison is not a recommendation. Standards and sources