ITOT vs SPY overlap - what they share and where they differ
ITOT and SPY share 88.1% of their weight across 500 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.
ITOT and SPY
88.1%
500 shared positions
ITOT
iShares Core S&P Total U.S. Stock Market ETF
Reported positions cover 100% of the fund, 2,426 positions · Jun 30, 2026
Top 10: 33.4%·Holdings of ITOT
SPY
SPY
Reported positions cover 100% of the fund, 500 positions · Jun 30, 2026
Top 10: 37.9%·Holdings of SPY
Reported positions cover ITOT 100%, SPY 100% of each fund. An overlap cannot exceed the smaller coverage, so a low figure can mean little overlap or thin reporting.
SPY vs ITOT side by side
ITOTiShares Core S&P Total U.S. Stock Market ETF
2,426
stock positions reported to the SEC
11.7% of its weight is in 1,926 names SPY does not hold
SPY
500
stock positions reported to the SEC
0.0% of its weight is in 0 names ITOT does not hold
Where each fund's weight sits
Largest sectors for both funds
The widest gap is Technology: SPY has 3.0 points more of it.
The figures side by side
| ITOT | SPY | |
|---|---|---|
| Filing date | Jun 30, 2026 | Jun 30, 2026 |
| Stock positions reported | 2,426 | 500 |
| Weight of the ten largest | 33.4% | 37.9% |
| Largest position | NVDA 6.6% | NVDA 7.5% |
| Held alone | 1,926 positions, 11.7% | 0 positions, 0.0% |
| Covered by stock positions | 100% | 100% |
Holdings they share
| Stock | In ITOT | In SPY | Counted |
|---|---|---|---|
| NVDANVIDIA Corp. | 6.63% | 7.52% | 6.63% |
| AAPLApple, Inc. | 5.81% | 6.59% | 5.81% |
| GOOGLAlphabet, Inc. | 5.15% | 5.84% | 5.15% |
| MSFTMicrosoft Corp. | 3.79% | 4.30% | 3.79% |
| AMZNAmazon.com, Inc. | 3.19% | 3.62% | 3.19% |
| AVGOBroadcom, Inc. | 2.45% | 2.77% | 2.45% |
| MUMicron Technology, Inc. | 1.78% | 2.02% | 1.78% |
| METAMeta Platforms, Inc. | 1.69% | 1.92% | 1.69% |
| TSLATesla, Inc. | 1.62% | 1.84% | 1.62% |
| AMDAdvanced Micro Devices, Inc. | 1.30% | 1.47% | 1.30% |
What each holds alone
The heaviest positions one fund reports and the other does not.
Only in ITOT
Only in SPY
Nothing among its reported positions that the others do not also hold.
Questions people ask
Is ITOT the same as SPY?
88.1% of their weight sits in the same 500 holdings. ITOT also reports SPCX, SNOW, BE, which the other does not. Among its reported positions, SPY holds nothing the other does not also hold.
How is the overlap between ITOT and SPY 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 ITOT and 100% of SPY, so the number cannot exceed the smaller coverage.
Which holds more, SPY or ITOT?
ITOT reports 2,426 stock positions and SPY reports 500. 11.7% of ITOT's weight sits in names SPY does not hold, and 0.0% of SPY's weight in names ITOT does not hold. The ten largest positions are 33.4% of ITOT and 37.9% of SPY.
How do ITOT and SPY differ by sector?
The widest gap is Technology: SPY has 3.0 points more of it. 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
ITOT against other funds in the table
SPY 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.