VOO vs VTI: How Much Of One Fund Is The Other?
VOO and VTI are Vanguard index ETFs with the same 0.03% expense ratio. VOO tracks the S&P 500, about 500 large US companies, while VTI tracks the Morningstar US Total Market Index of roughly 3,500. On 31 Aug 2026, 88.9% of VTI's stock holdings by value were companies VOO also held.
These are two of the most-owned funds in the United States, from the same company, at the same price. The honest comparison is less about which is better and more about how much of one you already own when you buy the other. Vanguard publishes every holding of both, so that can be measured rather than guessed.
What each one is
VOO is the Vanguard S&P 500 ETF. It tracks the S&P 500, the index of about 500 large US companies chosen by a committee at S&P Dow Jones Indices. Vanguard’s data lists its inception as 7 Sep 2010, its expense ratio as 0.03% (as of 28 Apr 2026) and 505 stocks as of 31 Aug 2026.
VTI is the Vanguard Morningstar Total Stock Market ETF. It tracks the Morningstar US Total Market Index, which covers the US market from the largest companies down to micro caps. Vanguard’s data lists its inception as 24 May 2001, its expense ratio as 0.03% (as of 28 Apr 2026) and 3,507 stocks as of 31 Aug 2026, against 3,450 in the index.
The name changed in 2026; the fund did not. Morningstar acquired the index provider CRSP in February 2026, and its press release of 28 Jul 2026 said the CRSP US Total Market Index is now the Morningstar US Total Market Index, with “naming only” affected. Vanguard’s press release of 29 Apr 2026 set the fund renaming for 29 Jul 2026 and said it “will not affect the funds’ investment objectives or how they are managed.”
Both are index funds sold as exchange-traded funds. Each also exists as a Vanguard mutual fund share class, which is why Vanguard reports the fund’s total assets, $1.8 trillion for the S&P 500 fund and $2.3 trillion for the total market fund at 31 Aug 2026, well above the ETF share classes alone.
Where they differ
Breadth. The downloadable holdings lists, dated 31 Aug 2026, carry 503 stock lines for VOO and 3,471 for VTI. Everything VOO adds to a portfolio is large; VTI adds mid-sized, small-cap and micro companies on top.
Concentration. The ten largest holdings were 37.81% of VOO and 33.41% of VTI. The names were the same ten in the same order, led by NVIDIA at 8.08% of VOO and 6.87% of VTI; VTI simply spreads the remaining weight across more companies.
Size of the typical company. Vanguard reports a median market capitalization of $436.0 billion for VOO and $348.3 billion for VTI. The gap is smaller than the holdings count suggests, because the extra 2,970 companies are small enough to barely move the weighted figure.
Who chooses. The S&P 500 is maintained by a committee at S&P Dow Jones Indices, which announces each addition and removal. The total market index is built to cover the investable US market from the largest companies to micro caps, so it is defined by breadth rather than by a list of 500.
How much they overlap
Most of VTI is VOO. Matching the two holdings lists by security code, 501 of VOO’s 503 holdings also appear in VTI. Those 501 companies made up 88.9% of the market value of VTI’s stock holdings on 31 Aug 2026. The other 2,970 companies in VTI made up the remaining 11.1%.
Two of VOO’s holdings were missing from VTI’s list: NXP Semiconductors and Amcor, together 0.12% of VOO. Both companies are incorporated outside the United States, and each index provider sets its own rules for companies like that.
So the difference between the funds is one slice of about a ninth of VTI. Whether that slice is worth owning is the whole decision, and it is a decision about small and mid-sized US companies, not about Vanguard.
A worked example
Take a hypothetical $10,000 in each fund. At 0.03%, each costs $10,000 times 0.0003, which is $3 a year, taken inside the fund. The expense ratio page shows how that compares with more expensive funds.
In VTI, 11.1% of the $10,000, about $1,109, sits in the 2,970 companies VOO does not hold. Spread across 2,970 names, that is an average of about 37 cents per company, though in practice it is weighted toward the larger ones.
Now split $10,000 evenly between the two. The VOO half is all S&P 500. Of the VTI half, 88.9% is the same companies again, so only about $554.50 of the $10,000 is anything VOO did not already hold. Holding both funds puts 94.5% of the money in companies VOO holds.
Which one to use
Use VTI when you want one fund to be the entire US stock market, including the small and mid-sized companies the S&P 500 leaves out, and you do not want to add a separate small-cap fund later.
Use VOO when you specifically want the S&P 500: when a plan, a benchmark or a three-fund portfolio calls for large US companies only, or when you intend to hold a separate small-cap or extended-market fund alongside it.
Use one, not both, when the goal is simplicity. The worked example shows that a 50/50 split adds a slice worth about 5.5% of the money. That is a small tilt, not diversification, and it doubles the number of positions to rebalance and track.
The original data
The data: Vanguard’s own holdings lists for both funds, as of 31 Aug 2026, 503 lines for VOO and 3,471 for VTI, downloaded from the data behind Vanguard’s fund pages on 25 Sep 2026 and matched by security code. The match is published as a CSV of VTI’s holdings alongside VOO’s holdings.
And every daily adjusted close for both ETFs from Yahoo Finance, which includes reinvested dividends. Over the 4,035 trading days they shared, from 9 Sep 2010 to 24 Sep 2026, a hypothetical $10,000 grew to $92,643 in VOO and $88,564 in VTI, before taxes. Their daily returns had a correlation of 0.996.
Year by year, from 2011 to 2025, VTI beat VOO in 4 years and trailed it in 11. The median gap was 0.73 percentage points. The widest was 2021, when VOO returned 28.79% and VTI 25.68%, a gap of 3.11 points. VTI’s best year against VOO was 2020, ahead by 2.75 points. The table is published as a CSV of both funds’ calendar-year returns.
In the 24,971-video search study, 5 titles name VOO and 1 names VTI. One channel made a complete guide to each: its VOO guide has 152,891 views and its VTI guide 18,625, about 8.2 times fewer for the broader fund from the same creator.
When it fails
Reading the 11-to-4 record as a verdict fails. Those fifteen years were led by the largest US companies, which both funds hold and VOO holds more heavily. In a stretch when smaller companies lead, the record can reverse, and 2020 showed VTI ahead by 2.75 points in a single year.
Treating VOO as diversified across the US market fails at the edges. It holds no small-cap companies by design, so an investor who believes they own “the market” through VOO owns about 88.9% of it by value.
Buying both for diversification fails, as the worked example shows: about 94.5% of the money lands in the same S&P 500 companies either way.
Comparing the headline stock counts fails too. Vanguard’s characteristics page and its holdings list give different counts for the same date, 505 against 503 for VOO and 3,507 against 3,471 for VTI, so quote the source you used and do not mix them.
And the figures here age. The overlap, the ten largest weights and the expense ratios were read on 25 Sep 2026. Vanguard updates holdings monthly, so check the fund page’s date before relying on any of them.
Related
The S&P 500 page explains the index VOO follows and how often it has fallen. Choosing an index fund sets out the order of the decision: the index first, the fee second. And ETFs vs index funds covers the difference between the ETF and mutual fund versions of funds like these.
Decide whether you want the small companies before comparing the two funds’ past returns. The returns differ by less than a point in most years; the question of whether to own 2,970 extra companies is the actual choice, and it does not change with last year’s winner.
— Michael Whitman
This page is educational, not financial advice. Test every idea on your own charts before risking money.