How much ETFs actually overlap

Put $10,000 into VOO and $10,000 into QQQ, and $10,900 of that money sits in the same 88 companies. Two tickers, two expense ratios, and just over half of the second fund is the first one again.

Vestiio stores the full constituent list of every fund it covers, taken from the fund’s own Form N-PORT filing with the SEC. That gives 1,411 pairs of US funds with a real overlap figure, and 1,045 of those pairs overlap at all. This note is what the figures say: where the duplication is, where it is not, and which of it is worth knowing about.

54.5%VOO against QQQ, the pair compared most

70.4%VIG against DGRO, two dividend growth funds

0.14%VTI against VXUS, the two fund portfolio

What overlap means here

For every company both funds hold, take the smaller of the two weights, and add those up. Two funds each putting 6% into Apple overlap by 6 points there. One at 6% against one at 2% overlaps by 2, because only 2 points of the money is doubled. The result is the share of a 50/50 split that ends up in the same companies.

It is deliberately a question about money rather than names. Two funds can hold 500 identical companies and still put the money in very different places, and a count of shared names would hide that.

What gets doubled is usually Nvidia

Of the 1,045 pairs that overlap at all, the single largest shared position is Nvidia in 337 of them, almost a third. Broadcom is next at 55, then Apple at 53, Intel at 27 and Microsoft at 22. Counting Nvidia, Apple and Microsoft together, one of the three is the biggest thing being doubled in 412 pairs, or 39%.

That is what fund overlap mostly is in practice. Not a broad smear of repeated companies, but the same few very large ones arriving twice through different doors.

Most pairs are fine. The popular ones are not.

Of the 1,411 pairs, 766 overlap by less than 10%, and only 28 by more than 90%. Redundancy is not a general property of index funds. It sits precisely in the combinations people actually choose.

VOO and VUG: 57.5%, 121 companies in both.
VOO and VOOG: 65.8%, 145 companies.
QQQ and VUG: 59.2%, 56 companies.
QQQ and XLK: 58.0%, 36 companies.
VOO and QQQ: 54.5%, 88 companies.
VOO and SCHG: 53.1%, 121 companies.
VUG and SCHG: 78.1%, 91 companies.

Take VOO and QQQ, the pair written about most. Held equally, 54.5% of the money lands in the same 88 companies, and the three largest of them are Nvidia at 7.5% of QQQ, Apple at 6.6% and Microsoft at 4.3%. The growth tilt is real; it is just much smaller than the two tickers suggest, because half of the second fund is the first one again.

Dividend funds are the opposite of interchangeable

This is where the assumption breaks in the other direction. Dividend funds are often treated as one category, where picking two is obviously redundant. The figures say something more interesting.

SCHD against VOO: 7.6%. Close to a genuine diversifier for an S&P 500 holding.
SCHD and VIG: 14.3%.
SCHD and DGRO: 20.1%.
SCHD and VYM: 21.3%.
VYM and VIG: 60.6%, 209 companies.
VIG and DGRO: 70.4%, 249 companies.

So SCHD sits apart from the others, while VIG and DGRO, two dividend growth funds bought as though they were different strategies, share 249 companies and 70% of their weight. Category names are a poor guide. The holdings are the guide.

The two fund portfolio holds up

VTI and VXUS, the total US market beside the total international market, overlap by 0.14%: four companies, all tiny. The classic two fund portfolio really does buy two different things, which is worth saying plainly in a note that spends most of its length on duplication. VT beside VTI is a different matter at 60.2%, since a global fund already holds the US market inside it.

Same companies, different money

VOO and RSP share 496 companies, essentially the whole S&P 500, yet overlap by 44.4%. RSP weights every company equally, so the money goes to very different places even though the list is identical. It is the clearest case for measuring weight rather than counting names.

At the other end, SPY, IVV, VOO and SPYM pair at 99.6% to 99.9%. Holding two of them is not a tilt of any kind.

What this does not tell you

Overlap is not a verdict. Two funds overlapping 55% may still be a deliberate, sensible choice, as long as it is a choice.
Filings describe one date. A fund’s constituents are as of its latest N-PORT filing, not this morning.
Coverage varies. Each fund page states how much of its weight the filing accounts for, and pairs whose coverage is too thin to support a figure are not published.
This is informational research, not investment advice, and nothing here is a recommendation to buy or sell anything.

Check any pair yourself

Every figure here is on a page you can open without an account.

A pair is one question. The one that matters is what a whole portfolio owns once every fund in it is opened, which is what Vestiio does with the funds you actually hold.

Computed on 23 September 2026 from the constituents Vestiio stores from each fund’s own SEC Form N-PORT filing, read through the public endpoint /api/v1/public/etf-overlap/<ticker>.json: 61 funds, 1,411 pairs. Figures were recomputed after the holding-key fix of the same day, which stopped unidentified holdings being matched between funds. Every pair named above can be checked on its own page or in the overlap tool.