ETF comparison
IWS vs MDY
Both US Mid Cap.
iShares Russell Mid-Cap Value ETF · State Street SPDR S&P MIDCAP 400 ETF Trust
Holdings overlap
272 positions appear in both funds. Buying equal dollars of IWS and MDY would leave roughly 22.6% of each dollar exposed to the same underlying securities.
Unmatched is the part of a fund's weight the other fund doesn't match: names only it holds, plus any extra weight it puts in names both funds hold.
Side by side
Sub-score comparison
Tracking quality isn't part of the composite — see what we don't score for why.
Cost difference
Expense ratios are effectively identical (0.23% vs 0.23%).
Fee figure is the annual expense charged on $100,000. To see how the gap compounds over a multi-decade holding period, open the cost calculator pre-filled with IWS vs MDY.
Top shared holdings
272 shared in total| # | Holding | In IWS | In MDY | Overlap |
|---|---|---|---|---|
| 1 | MKS INC | 0.27% | 0.54% | 0.27% |
| 2 | TWILIO INC | 0.25% | 1.30% | 0.25% |
| 3 | ENTEGRIS INC | 0.23% | 0.73% | 0.23% |
| 4 | OKTA INC | 0.22% | 1.01% | 0.22% |
| 5 | UNITED THERAPEUTICS CORP | 0.22% | 0.67% | 0.22% |
| 6 | US FOODS HOLDING CORP | 0.22% | 0.60% | 0.22% |
| 7 | RB GLOBAL INC | 0.21% | 0.43% | 0.21% |
| 8 | TD SYNNEX CORP | 0.20% | 0.64% | 0.20% |
| 9 | RELIANCE INC | 0.19% | 0.59% | 0.19% |
| 10 | ITT INC | 0.17% | 0.53% | 0.17% |
| 11 | EAST WEST BANCORP INC | 0.17% | 0.50% | 0.17% |
| 12 | NEXTPOWER INC | 0.17% | 0.37% | 0.17% |
Only in IWS
448 total- WARNER BROS. DISCOVERY INC 0.63%
- PHILLIPS 66 0.62%
- DIGITAL REALTY TRUST INC 0.62%
- KINDER MORGAN INC 0.61%
- ALLSTATE CORP (THE) 0.60%
- HEWLETT PACKARD ENTERPRISE COMPANY 0.59%
- FLEX LTD 0.58%
- REALTY INCOME CORP 0.57%
- DELTA AIR LINES INC 0.56%
- CORTEVA INC 0.56%
Only in MDY
129 total- U.S. Dollar 0.89%
- nVent Electric plc 0.79%
- TechnipFMC plc 0.77%
- ATI Inc 0.75%
- MACOM Technology Solutions Holdings Inc. 0.64%
- XPO Inc. 0.62%
- Woodward Inc. 0.56%
- Roivant Sciences Ltd. 0.55%
- Carpenter Technology Corporation 0.55%
- Lattice Semiconductor Corporation 0.55%
Related comparisons
More comparisons with IWS
- IWS vs VYM · Vanguard High Dividend Yield Index Fund ETF Shares 21.3%
- IWS vs VTV · Vanguard Morningstar Value ETF 18.8%
- IWS vs IJJ · iShares S&P Mid-Cap 400 Value ETF 18.2%
- IWS vs DGRO · iShares Core Dividend Growth ETF 16.2%
- IWS vs VOT · Vanguard Morningstar Mid-Cap Growth ETF 16.2%
- IWS vs VTI · Vanguard Morningstar Total Stock Market ETF 15.3%
More comparisons with MDY
- MDY vs IWR · iShares Russell Mid-Cap ETF 21.7%
- MDY vs IWP · iShares Russell Mid-Cap Growth ETF 17.3%
- MDY vs IWM · iShares Russell 2000 ETF 11.0%
- MDY vs IWD · iShares Russell 1000 Value ETF 6.8%
- MDY vs VTI · Vanguard Morningstar Total Stock Market ETF 5.0%
- MDY vs ITOT · iShares Core S&P Total U.S. Stock Market ETF 4.8%
Percentages are holdings overlap with the named fund.
Open IWS or MDY at a brokerage
Both funds trade commission-free at major US brokerages.
Affiliate links — opening an account through these earns PlainIndex a one-time referral. Scoring is computed before any affiliate consideration; see our methodology and funding disclosure.
Holdings overlap is the sum of min(weight_a, weight_b) over positions
matched on ISIN (CUSIP fallback). Methodology: see
/methodology/.
Comparing two funds doesn't endorse swapping one for the other. Tax-lot history, account type, and personal goals matter — PlainIndex publishes data and methodology, not investment advice.