Data as of Sep 12, 2026. Both funds on the fields they both publish, from the same sources.
IWB vs SPY: how they differ
IWB and SPY hold 90% of their weight in the same names, and SPY returned more over the year.
iShares Russell 1000 ETF and SPDR S&P 500 ETF Trust.
What they hold in common
By the books each fund has filed, IWB and SPY hold 90% of their money in the same securities at the same weight.
| Holding | IWB | SPY |
|---|---|---|
| NVIDIA CORPORATION | 6.73% | 7.52% |
| APPLE INC. | 6.03% | 6.59% |
| MICROSOFT CORPORATION | 4.00% | 4.30% |
| AMAZON.COM, INC. | 3.33% | 3.62% |
| ALPHABET INC. | 3.00% | 3.25% |
| BROADCOM INC. | 2.54% | 2.77% |
| ALPHABET INC. | 2.42% | 2.59% |
| MICRON TECHNOLOGY, INC. | 1.88% | 2.02% |
| META PLATFORMS, INC. | 1.79% | 1.92% |
| TESLA, INC. | 1.77% | 1.84% |
| ELI LILLY AND COMPANY | 1.38% | 1.47% |
| ADVANCED MICRO DEVICES, INC. | 1.36% | 1.47% |
| Only in IWB | Only in SPY |
|---|---|
| LINDE PUBLIC LIMITED COMPANY 0.34% | Linde plc 0.37% |
| EATON CORPORATION PUBLIC LIMITED COMPANY 0.24% | Seagate Technology Holdings plc 0.34% |
| Chubb Limited 0.17% | Eaton Corp. plc 0.26% |
| TRANE TECHNOLOGIES PUBLIC LIMITED COMPAN 0.16% | Chubb Ltd. 0.19% |
| MEDTRONIC PUBLIC LIMITED COMPANY 0.14% | Trane Technologies plc 0.17% |
| SPACE EXPLORATION TECHNOLOGIES CORP. 0.13% | Medtronic plc 0.16% |
| JOHNSON CONTROLS INTERNATIONAL PUBLIC LI 0.13% | Johnson Controls International plc 0.14% |
| SNOWFLAKE INC. 0.12% | Royal Caribbean Cruises Ltd. 0.12% |
Weight overlap is an ETFIQ calculation: for every security both funds hold, the smaller of the two weights, summed. Above 50%, holding both is close to holding one of them twice. Holdings dated Jun 30, 2026.
| IWB iShares Russell 1000 ETF | SPY SPDR S&P 500 ETF Trust | |
|---|---|---|
| Where it sits | Core index fund | Core index fund |
| Issuer | iShares | State Street |
| What it is | Russell 1000 | S&P 500, book from IVV |
| Total return, 1 year | +16.7% | +17.5% |
| S&P 500 over the same days | +17.5% | +17.5% |
| Gap to the S&P 500 | −0.8 pts | 0.0 pts |
| Expense ratio | 0.15% | 0.09% |
| Already in the S&P 500 | 91.9% | 100.0% |
| Holdings | 1024 | 504 |
IWB in plain words
IWB is an index equity fund tracking the Russell 1000. Over the year to Sep 11, 2026 it returned +16.7% with distributions reinvested, against +17.5% for the S&P 500 and +23.0% for the Nasdaq-100. The prospectus expense ratio is 0.15% a year. By its holdings filed for Jun 30, 2026, 92% of the fund by weight is stocks the S&P 500 also holds, across 1024 positions, with the top ten at 33.5%.
SPY in plain words
SPY is an index equity fund tracking the S&P 500. Over the year to Sep 11, 2026 it returned +17.5% with distributions reinvested, against +17.5% for the S&P 500 and +23.0% for the Nasdaq-100. The prospectus expense ratio is 0.09% a year. By its holdings filed for Jun 30, 2026, 100% of the fund by weight is stocks the S&P 500 also holds, across 504 positions, with the top ten at 36.4%.
Questions people ask
- Which returned more over the last year, IWB or SPY?
- In the year to Sep 12, 2026, with distributions reinvested, IWB returned +16.7% and SPY returned +17.5%, so SPY returned more. One year is one year; the longer windows are in the table.
- Which is cheaper, IWB or SPY?
- IWB charges 0.15% a year and SPY charges 0.09%, so SPY is cheaper. Fees come from each fund's prospectus.
- How much do IWB and SPY overlap with the S&P 500?
- By their latest filed holdings, 92% of IWB and 100% of SPY by weight is stocks the S&P 500 already holds. Between the two funds, 90% of their books are the same securities at the same weight.
Other comparisons
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Where these figures came from
ETFIQ links to the documents behind every figure. It is not affiliated with any issuer, and a link is not an endorsement.
Cite this page. ETFIQ, IWB against SPY, data as of Sep 12, 2026. https://etfiq.com/compare/any/IWB-SPY Free to use with attribution; the underlying files are at Open data.
A comparison is not a recommendation. Standards and sources