ETF comparison
IWB vs SPY
Both US Large Cap.
iShares Russell 1000 ETF · State Street SPDR S&P 500 ETF Trust
Holdings overlap
496 positions appear in both funds. Buying equal dollars of IWB and SPY would leave roughly 85.1% 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
SPY is 6 bps cheaper than IWB. On a $100,000 position that's about $56/yr more in fees for IWB.
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 IWB vs SPY.
Top shared holdings
496 shared in total| # | Holding | In IWB | In SPY | Overlap |
|---|---|---|---|---|
| 1 | NVIDIA CORPORATION | 6.72% | 7.30% | 6.72% |
| 2 | APPLE INC. | 6.03% | 7.69% | 6.03% |
| 3 | MICROSOFT CORPORATION | 3.99% | 6.22% | 3.99% |
| 4 | AMAZON.COM, INC. | 3.33% | 3.94% | 3.33% |
| 5 | ALPHABET INC. | 3.00% | 2.56% | 2.56% |
| 6 | BROADCOM INC. | 2.53% | 2.33% | 2.33% |
| 7 | ALPHABET INC. | 2.42% | 2.06% | 2.06% |
| 8 | META PLATFORMS, INC. | 1.78% | 2.09% | 1.78% |
| 9 | TESLA, INC. | 1.77% | 1.64% | 1.64% |
| 10 | ELI LILLY AND COMPANY | 1.38% | 1.71% | 1.38% |
| 11 | MICRON TECHNOLOGY, INC. | 1.87% | 1.35% | 1.35% |
| 12 | BERKSHIRE HATHAWAY INC. | 1.34% | 1.63% | 1.34% |
Only in IWB
528 total- EXXON MOBIL CORPORATION 0.82%
- SPACE EXPLORATION TECHNOLOGIES CORP. 0.13%
- SNOWFLAKE INC. 0.12%
- CLOUDFLARE, INC. 0.11%
- Astera Labs, Inc 0.11%
- SPOTIFY TECHNOLOGY S.A. 0.10%
- WARNER BROS. DISCOVERY, INC. 0.09%
- CORTEVA, INC. 0.08%
- ONEOK, INC. 0.08%
- ROCKET LAB CORPORATION 0.08%
Only in SPY
8 total- EXXONMOBIL HOLDINGS CORP 1.05%
- SEAGATE TECHNOLOGY HOLDINGS 0.19%
- NXP SEMICONDUCTORS NV 0.10%
- TE CONNECTIVITY PLC 0.10%
- ONEOK INC 0.08%
- VYLOR INC 0.07%
- ERIE INDEMNITY COMPANY CL A 0.01%
- SKYDANCE CORP 0.01%
Related comparisons
More comparisons with IWB
- IWB vs MGC · Vanguard Morningstar Mega Cap ETF 74.8%
- IWB vs OEF · iShares S&P 100 ETF 66.1%
- IWB vs FELC · Fidelity Enhanced Large Cap Core ETF 63.5%
- IWB vs FNDX · Schwab Fundamental U.S. Large Company ETF 61.3%
- IWB vs IWD · iShares Russell 1000 Value ETF 59.2%
- IWB vs XLG · Invesco S&P 500 Top 50 ETF 57.2%
More comparisons with SPY
- SPY vs DFAU · Dimensional US Core Equity Market ETF 83.2%
- SPY vs SPTM · State Street SPDR Portfolio S&P 1500 Composite Stock Market ETF 82.9%
- SPY vs VTI · Vanguard Morningstar Total Stock Market ETF 82.6%
- SPY vs MGC · Vanguard Morningstar Mega Cap ETF 82.6%
- SPY vs ESGV · Vanguard ESG U.S. Stock ETF 81.0%
- SPY vs IWV · iShares Russell 3000 ETF 80.5%
Percentages are holdings overlap with the named fund.
Open IWB or SPY 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.