ETF comparison
IWR vs SPMD
Both US Mid Cap.
iShares Russell Mid-Cap ETF · State Street SPDR Portfolio S&P 400 Mid Cap ETF
Holdings overlap
317 positions appear in both funds. Buying equal dollars of IWR and SPMD would leave roughly 22.9% 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
SPMD is 15 bps cheaper than IWR. On a $100,000 position that's about $150/yr more in fees for IWR.
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 IWR vs SPMD.
Top shared holdings
317 shared in total| # | Holding | In IWR | In SPMD | Overlap |
|---|---|---|---|---|
| 1 | Twilio, Inc. | 0.22% | 0.86% | 0.22% |
| 2 | MKS, Inc. | 0.22% | 0.83% | 0.22% |
| 3 | Carpenter Technology Corp. | 0.22% | 0.84% | 0.22% |
| 4 | Curtiss-Wright Corp. | 0.20% | 0.77% | 0.20% |
| 5 | Entegris, Inc. | 0.20% | 0.76% | 0.20% |
| 6 | nVent Electric plc | 0.20% | 0.76% | 0.20% |
| 7 | Illumina, Inc. | 0.19% | 0.73% | 0.19% |
| 8 | ATI, Inc. | 0.19% | 0.74% | 0.19% |
| 9 | TechnipFMC plc | 0.19% | 0.73% | 0.19% |
| 10 | MasTec, Inc. | 0.19% | 0.71% | 0.19% |
| 11 | MACOM Technology Solutions Holdings, Inc. | 0.18% | 0.69% | 0.18% |
| 12 | Woodward, Inc. | 0.18% | 0.70% | 0.18% |
Only in IWR
507 total- Datadog, Inc. 0.62%
- Snowflake, Inc. 0.61%
- Royal Caribbean Cruises Ltd. 0.58%
- Cloudflare, Inc. 0.56%
- Robinhood Markets, Inc. 0.56%
- Teradyne, Inc. 0.55%
- Marathon Petroleum Corp. 0.54%
- Astera Labs, Inc. 0.53%
- Simon Property Group, Inc. 0.52%
- United Rentals, Inc. 0.51%
Only in SPMD
83 total- Moog Inc 0.33%
- Cytokinetics Inc 0.32%
- UMB Financial Corp 0.28%
- CareTrust REIT Inc 0.26%
- Old National Bancorp/IN 0.25%
- EnerSys 0.24%
- FirstCash Holdings Inc 0.23%
- Terex Corp 0.23%
- Autoliv Inc 0.22%
- HealthEquity Inc 0.21%
Related comparisons
More comparisons with IWR
- IWR vs IVOO · Vanguard S&P Mid-Cap 400 Index Fund ETF Shares 22.8%
- IWR vs VYM · Vanguard High Dividend Yield Index Fund ETF Shares 22.6%
- IWR vs MDY · State Street SPDR S&P MIDCAP 400 ETF Trust 21.7%
- IWR vs VTV · Vanguard Morningstar Value ETF 19.9%
- IWR vs VTI · Vanguard Morningstar Total Stock Market ETF 18.8%
- IWR vs ITOT · iShares Core S&P Total U.S. Stock Market ETF 18.7%
More comparisons with SPMD
- SPMD vs IWP · iShares Russell Mid-Cap Growth ETF 20.0%
- SPMD vs IWM · iShares Russell 2000 ETF 11.2%
- SPMD vs IWD · iShares Russell 1000 Value ETF 6.8%
- SPMD vs ITOT · iShares Core S&P Total U.S. Stock Market ETF 5.0%
- SPMD vs VTI · Vanguard Morningstar Total Stock Market ETF 5.0%
- SPMD vs SCHB · Schwab U.S. Broad Market ETF 4.8%
Percentages are holdings overlap with the named fund.
Open IWR or SPMD 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.