IWF vs MDY: how much do they overlap?
iShares Russell 1000 Growth ETF (IWF) · SPDR S&P MIDCAP 400 ETF Trust (MDY)
overlap by weight · 95 shared holdings
IWF: 387 holdings (as of 2026-03-31) · MDY: 400 holdings (as of 09-Jul-2026)
Note: the two funds' latest official filings have different dates, which can understate overlap slightly for funds tracking similar indexes.
Low overlap
What this means
IWF and MDY hold mostly different stocks. Combining them genuinely spreads your exposure across different parts of the market.
Overlap by weight sums the smaller of the two funds' weights for every stock they both hold — it answers "how much of my money is in the same stocks either way?" See methodology.
Top shared holdings
| Company | Ticker | in IWF | in MDY |
|---|---|---|---|
| BURLINGTON STORES, INC. | BURL | 0.07% | 0.56% |
| EVERPURE, INC. | P | 0.06% | 0.71% |
| Somnigroup International Inc. | SGI | 0.05% | 0.44% |
| GUIDEWIRE SOFTWARE, INC. | GWRE | 0.05% | 0.32% |
| PENUMBRA, INC. | PEN | 0.04% | 0.35% |
| TOAST, INC. | TOST | 0.04% | 0.38% |
| TEXAS ROADHOUSE, INC. | TXRH | 0.04% | 0.34% |
| NEUROCRINE BIOSCIENCES, INC. | NBIX | 0.04% | 0.5% |
| LAMAR ADVERTISING COMPANY | LAMR | 0.04% | 0.39% |
| DYNATRACE, INC. | DT | 0.04% | 0.37% |
FAQ
How much do IWF and MDY overlap?
IWF and MDY have a 1.5% overlap by weight, sharing 95 holdings (out of 387 in IWF and 400 in MDY), based on official issuer holdings as of 2026-03-31.
What does 1.5% overlap mean?
IWF and MDY hold mostly different stocks. Combining them genuinely spreads your exposure across different parts of the market.
Which stocks do IWF and MDY both hold?
The largest shared positions are BURLINGTON STORES, INC., EVERPURE, INC., Somnigroup International Inc., GUIDEWIRE SOFTWARE, INC., PENUMBRA, INC.. The full list of top shared holdings with weights in each fund is shown on this page.