IWR vs MDY: holdings overlap, shared companies and scores
As of September 11, 2026, IWR and MDY overlap 22.2% by weight. iShares Russell Mid-Cap ETF (IWR): Russell Midcap index. State Street SPDR S&P MIDCAP 400 ETF Trust (MDY): U.S. mid-cap stocks.
Updated September 11, 2026
How much do IWR and MDY overlap?
As of September 11, 2026, IWR and MDY overlap 22.2% by weight.
22% of IWR is already inside MDY.
88% of MDY is already inside IWR.
IWR holds 821 companies and MDY holds 396; 314 are in both.
Computed by ETF Copilot from both funds' holdings rather than quoted from a data provider, and rebuilt nightly.
How does ETF Copilot score IWR and MDY?
As of September 11, 2026, ETF Copilot scores IWR 4.9 out of 10 and MDY 4.3 out of 10.
They differ most on Valuation: IWR 7.1 and MDY 5.1.
The five factor scores behind them are set out below, 0–10 and higher is better, ranked against every US equity ETF we track.
| Factor | IWR | MDY |
|---|---|---|
| Growth | 5.8 | 6.1 |
| Valuation | 7.1 | 5.1 |
| Risk | 3.9 | 3.7 |
| Quality | 2.9 | 1.9 |
| Return | 4.7 | 4.1 |
IWR is the cheaper of the two at 0.18% a year
As of September 11, 2026, IWR charges 0.18% a year, yields 1.54% and holds $57.0B in assets across 821 positions.
As of September 11, 2026, MDY charges 0.23% a year, yields 1.28% and holds $26.5B in assets across 396 positions.
| Measure | IWR | MDY |
|---|---|---|
| Expense ratio | 0.18% | 0.23% |
| Dividend yield | 1.54% | 1.28% |
| Assets under management | $57.0B | $26.5B |
| Holdings | 821 | 396 |
Expense ratio, dividend yield and assets under management are reported by the fund and refreshed daily. Every other figure on this page is computed by ETF Copilot.
Where IWR and MDY trade against their own history
IWR trades at 20.2 times earnings, against its own median of 19.6, and is more expensive than 54% of its own 114 monthly readings since 2017.
MDY trades at 20.2 times earnings, against its own median of 18.6, and is more expensive than 69% of its own 114 monthly readings since 2017.
What moved IWR and MDY this week
IWR fell 2.0% in the week to September 11, 2026. The holdings that moved it most were Snowflake (−7.7%), Robinhood Markets (−9.7%) and Autodesk (−10.6%); Hewlett Packa (+14.1%) pushed the other way.
MDY fell 1.7% in the week to September 11, 2026. The holdings that moved it most were Guidewire Software (−30.5%), Illumina (−6.9%) and Twilio (−5.5%); Semtech (+23.5%) pushed the other way.
What do IWR and MDY each hold?
What's inside IWR: Tech 18%, AI 3%.
6% of IWR is its ten largest holdings.
What's inside MDY: Tech 16%, Semiconductors 4%.
8% of MDY is its ten largest holdings.
Compare with similar funds
Cite this
ETF Copilot, “IWR vs MDY holdings overlap and scores”, as of September 11, 2026.
https://etf-copilot.com/compare/iwr-vs-mdy
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