OEF vs SPY overlap - what they share and where they differ
OEF and SPY share 71.7% of their weight across 101 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.
OEF and SPY
71.7%
101 shared positions
OEF
iShares S&P 100 ETF
Reported positions cover 100% of the fund, 101 positions · Jun 30, 2026
Top 10: 52.8%·Holdings of OEF
SPY
SPY
Reported positions cover 100% of the fund, 500 positions · Jun 30, 2026
Top 10: 37.9%·Holdings of SPY
Reported positions cover OEF 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 OEF side by side
OEFiShares S&P 100 ETF
101
stock positions reported to the SEC
0.0% of its weight is in 0 names SPY does not hold
SPY
500
stock positions reported to the SEC
28.2% of its weight is in 399 names OEF does not hold
Where each fund's weight sits
Largest sectors for both funds
The widest gap is Technology: OEF has 7.7 points more of it.
The figures side by side
| OEF | SPY | |
|---|---|---|
| Filing date | Jun 30, 2026 | Jun 30, 2026 |
| Stock positions reported | 101 | 500 |
| Weight of the ten largest | 52.8% | 37.9% |
| Largest position | NVDA 10.5% | NVDA 7.5% |
| Held alone | 0 positions, 0.0% | 399 positions, 28.2% |
| Covered by stock positions | 100% | 100% |
Holdings they share
| Stock | In OEF | In SPY | Counted |
|---|---|---|---|
| NVDANVIDIA CORP | 10.47% | 7.52% | 7.52% |
| AAPLAPPLE INC | 9.18% | 6.59% | 6.59% |
| GOOGLALPHABET INC | 8.14% | 5.84% | 5.84% |
| MSFTMICROSOFT CORP | 5.99% | 4.30% | 4.30% |
| AMZNAMAZON.COM INC | 5.04% | 3.62% | 3.62% |
| AVGOBROADCOM INC | 3.86% | 2.77% | 2.77% |
| MUMICRON TECHNOLOGY INC | 2.81% | 2.02% | 2.02% |
| METAMETA PLATFORMS INC | 2.67% | 1.92% | 1.92% |
| TSLATESLA INC | 2.56% | 1.84% | 1.84% |
| AMDADVANCED MICRO DEVICES INC | 2.05% | 1.47% | 1.47% |
What each holds alone
The heaviest positions one fund reports and the other does not.
Only in OEF
Nothing among its reported positions that the others do not also hold.
Only in SPY
Questions people ask
Is OEF the same as SPY?
71.7% of their weight sits in the same 101 holdings. Among its reported positions, OEF holds nothing the other does not also hold. SPY also reports KLAC, SNDK, PANW, which the other does not.
How is the overlap between OEF 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 OEF and 100% of SPY, so the number cannot exceed the smaller coverage.
Which holds more, SPY or OEF?
OEF reports 101 stock positions and SPY reports 500. 0.0% of OEF's weight sits in names SPY does not hold, and 28.2% of SPY's weight in names OEF does not hold. The ten largest positions are 52.8% of OEF and 37.9% of SPY.
How do OEF and SPY differ by sector?
The widest gap is Technology: OEF has 7.7 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
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.