ETF comparison
IJR vs MDY
US Small Cap vs US Mid Cap.
iShares Core S&P Small-Cap ETF · State Street SPDR S&P MIDCAP 400 ETF Trust
Holdings overlap
5 positions appear in both funds. Buying equal dollars of IJR and MDY would leave roughly 1.4% 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
IJR is 17 bps cheaper than MDY. On a $100,000 position that's about $170/yr more in fees for MDY.
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 IJR vs MDY.
Top shared holdings
5 shared in total| # | Holding | In IJR | In MDY | Overlap |
|---|---|---|---|---|
| 1 | CORCEPT THERAPEUTICS INC | 0.45% | 0.32% | 0.32% |
| 2 | BRIGHTSPRING HEALTH SERVICES INC | 0.60% | 0.29% | 0.29% |
| 3 | MOLINA HEALTHCARE INC | 0.64% | 0.28% | 0.28% |
| 4 | BRINKER INTERNATIONAL INC | 0.39% | 0.25% | 0.25% |
| 5 | KRYSTAL BIOTECH INC | 0.53% | 0.25% | 0.25% |
Only in IJR
598 total- FORMFACTOR INC 0.67%
- VIASAT INC 0.66%
- ARGAN INC 0.60%
- ELEMENT SOLUTIONS INC 0.59%
- MAXLINEAR INC 0.58%
- ESCO TECHNOLOGIES INC 0.49%
- MATCH GROUP INC 0.48%
- ALKERMES PLC 0.47%
- EVERUS CONSTRUCTION GROUP INC 0.46%
- STONEX GROUP INC 0.46%
Only in MDY
396 total- Twilio Inc. Class A 1.30%
- Okta Inc. Class A 1.01%
- U.S. Dollar 0.89%
- nVent Electric plc 0.79%
- TechnipFMC plc 0.77%
- ATI Inc 0.75%
- Entegris Inc. 0.73%
- United Therapeutics Corporation 0.67%
- MACOM Technology Solutions Holdings Inc. 0.64%
- TD SYNNEX Corporation 0.64%
Related comparisons
More comparisons with IJR
- IJR vs IWP · iShares Russell Mid-Cap Growth ETF 1.3%
- IJR vs FELC · Fidelity Enhanced Large Cap Core ETF 1.2%
- IJR vs SCHD · Schwab U.S. Dividend Equity ETF 1.1%
- IJR vs FBCG · Fidelity Blue Chip Growth ETF 1.0%
- IJR vs JAVA · JPMorgan Active Value ETF 0.9%
- IJR vs LRGF · iShares U.S. Equity Factor ETF 0.8%
More comparisons with MDY
Percentages are holdings overlap with the named fund.
Open IJR 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.