IWB vs SPTM overlap - what they share and where they differ
IWB and SPTM share 95.2% of their weight across 858 common positions, read from what each fund reported to the SEC.
Each week Ploutos reads the reported positions of the largest US equity ETFs and measures, pair by pair, the weight they share: for every stock both funds hold, the smaller of the two weights counts. Two funds tracking the same index land near 100%. A sector fund inside a broad index fund lands at roughly that sector's weight.
IWB and SPTM
95.2%
858 shared positions
IWB
iShares Russell 1000 ETF
Reported positions cover 100% of the fund, 1,011 positions · Jun 30, 2026
Top 10: 34.8%·Holdings of IWB
SPTM
State Street(R) SPDR(R) Portfolio S&P 1500(R) Composite Stock Market ETF
Reported positions cover 100% of the fund, 1,490 positions · Jun 30, 2026
Top 10: 34.9%·Holdings of SPTM
Reported positions cover IWB 100%, SPTM 100% of each fund. An overlap cannot exceed the smaller coverage, so a low figure can mean little overlap or thin reporting.
SPTM vs IWB side by side
IWBiShares Russell 1000 ETF
1,011
stock positions reported to the SEC
3.6% of its weight is in 153 names SPTM does not hold
SPTMState Street(R) SPDR(R) Portfolio S&P 1500(R) Composite Stock Market ETF
1,490
stock positions reported to the SEC
3.7% of its weight is in 632 names IWB does not hold
Where each fund's weight sits
Largest sectors for both funds
No sector differs by more than a point between the two.
The figures side by side
| IWB | SPTM | |
|---|---|---|
| Filing date | Jun 30, 2026 | Jun 30, 2026 |
| Stock positions reported | 1,011 | 1,490 |
| Weight of the ten largest | 34.8% | 34.9% |
| Largest position | NVDA 6.7% | NVDA 6.9% |
| Held alone | 153 positions, 3.6% | 632 positions, 3.7% |
| Covered by stock positions | 100% | 100% |
Holdings they share
| Stock | In IWB | In SPTM | Counted |
|---|---|---|---|
| NVDANVIDIA CORPORATION | 6.72% | 6.92% | 6.72% |
| AAPLAPPLE INC. | 6.03% | 6.07% | 6.03% |
| GOOGLALPHABET INC. | 5.42% | 5.38% | 5.38% |
| MSFTMICROSOFT CORPORATION | 3.99% | 3.96% | 3.96% |
| AMZNAMAZON.COM, INC. | 3.33% | 3.33% | 3.33% |
| AVGOBROADCOM INC. | 2.53% | 2.56% | 2.53% |
| MUMICRON TECHNOLOGY, INC. | 1.87% | 1.86% | 1.86% |
| METAMETA PLATFORMS, INC. | 1.78% | 1.76% | 1.76% |
| TSLATESLA, INC. | 1.77% | 1.69% | 1.69% |
| AMDADVANCED MICRO DEVICES, INC. | 1.36% | 1.35% | 1.35% |
What each holds alone
The heaviest positions one fund reports and the other does not.
Only in IWB
Only in SPTM
Questions people ask
Is IWB the same as SPTM?
95.2% of their weight sits in the same 858 holdings. IWB also reports JOHNSON CONTROLS INTERNATIONAL PUBLIC LIMITED COMPANY, SPCX, BE, which the other does not. SPTM also reports STX, JCI, ACN, which the other does not.
How is the overlap between IWB and SPTM measured?
For every stock both funds report, the smaller of the two weights counts, and the sum is the overlap. The reported positions cover 100% of IWB and 100% of SPTM, so the number cannot exceed the smaller coverage.
Which holds more, SPTM or IWB?
IWB reports 1,011 stock positions and SPTM reports 1,490. 3.6% of IWB's weight sits in names SPTM does not hold, and 3.7% of SPTM's weight in names IWB does not hold. The ten largest positions are 34.8% of IWB and 34.9% of SPTM.
How do IWB and SPTM differ by sector?
No sector differs by more than a point between the two. Sectors come from each holding's SIC code in its SEC record, summed by the weight the fund reports.
Where do the numbers come from?
From each fund's own N-PORT filing to the SEC, which lists every position and its weight. The comparison uses every equity position the fund reports; cash, futures and bonds are not counted, which is why a coverage figure sits next to every result. Holdings change between filings.
Other pairs with these funds
IWB against other funds in the table
SPTM against other funds in the table
Add a third fund in the tool·All fund pairs
Descriptive data from public SEC filings. Nothing on this page is a recommendation to buy, sell or hold any fund or stock, and holdings change between filings.