VOO vs VTI: What Is Actually Different Between the Two Vanguard Funds

VOO and VTI are the two most argued-about tickers in index investing, and most of the argument is about a sliver. Both are Vanguard ETFs, both charge 0.03% a year, and by our reading of Vanguard's own fact sheets, something like 85 to 90 percent of VTI sits in the same companies VOO holds, in nearly the same proportions. The real difference is roughly 3,000 smaller companies that VTI owns and VOO does not, and what those companies have done to returns.

We build MarketCast, a stock market app for TVs, so we look at these two tickers side by side on a screen across the room more than most people. Below is what is actually different, with every fund number from Vanguard's fact sheets as of September 30, 2026. This is an explanation, not a recommendation. Nothing here is investment advice, and we do not tell anyone which fund to buy.

VOO vs VTI at a glance

Source: Vanguard fact sheets for VOO and VTI, as of September 30, 2026. Expense ratios are as reported in each fund's most recent prospectus. The asset totals include the mutual fund share classes of the same funds; the ETF share classes alone were about $1.03 trillion for VOO and $689 billion for VTI.

What VOO holds

VOO tracks the S&P 500: about 500 of the largest US companies, chosen by an index committee at S&P Dow Jones Indices and weighted by market value. Vanguard counts 505 stocks in the fund and 503 in the index. The index has more than 500 lines because a few companies, Alphabet among them, have two share classes in it. VOO buys every stock in the index at its index weight, which Vanguard calls full replication.

If you want the longer story of the S&P 500 itself and why so many people hold it, our earlier post on investing in VOO covers it, and our explainer on the S&P 500, Dow and Nasdaq covers how the indexes differ.

What VTI holds, and why its name changed

VTI tries to own the whole investable US stock market: large, mid and small companies, 3,519 stocks as of September 30. It uses what Vanguard calls an index-sampling strategy instead of buying every last name in exact proportion. It is also weighted by market value, so the giants still dominate. NVIDIA, Apple, Microsoft, Alphabet and Amazon are the top five in both funds, in the same order.

If the name looks unfamiliar, you are not imagining it. On July 29, 2026, Vanguard added "Morningstar" to the names of its US equity index funds that track the indexes formerly branded CRSP, after Morningstar rebranded the CRSP market indexes as part of its CRSP acquisition. The Vanguard Total Stock Market ETF is now the Vanguard Morningstar Total Stock Market ETF, and the CRSP US Total Market Index is now the Morningstar US Total Market Index. In its April 29 announcement, Vanguard said the renaming would not affect the funds' investment objectives or how they are managed, and the ticker is still VTI.

From the data side: brokerages, quote feeds and apps pick up fund name changes on their own schedules, so you will see both names for a while. Same fund. It is not even VTI's first index switch: the fact sheet notes it tracked the Dow Jones U.S. Total Stock Market Index (the old Wilshire 5000) through April 22, 2005, then the MSCI US Broad Market Index through June 2, 2013, then CRSP, now Morningstar.

How much do VOO and VTI overlap?

Practically every company in VOO is also in VTI, so the useful question runs the other way: how much of VTI is S&P 500 companies? S&P Dow Jones Indices has long described the S&P 500 as about 80 percent of the investable US market. The current fact sheets suggest the share is higher right now.

Look at the biggest holdings. NVIDIA is 8.4% of VOO and 7.1% of VTI. Apple is 7.4% and 6.6%. Microsoft is 5.8% and 5.2%. Each VTI weight comes out at roughly 0.85 to 0.9 times the VOO weight, and the top ten as a group are 40.6% of VOO and 36.1% of VTI, a ratio of about 0.89. Because both funds weight by market value, that ratio is close to the share of VTI that sits in S&P 500 companies. This is our arithmetic, not an official Vanguard number, but it puts the overlap in the mid to high 80s by weight as of September 30.

Put plainly, VTI behaves like VOO plus a 10 to 15 percent slice of mid and small caps. Holding both mostly means holding the same large companies twice. That is a description, not a judgment: some investors want exactly that weighting.

VOO vs VTI expense ratio: a tie

Both funds report a 0.03% expense ratio, which works out to $3 a year on every $10,000 invested. For context, Vanguard's fact sheets put the average S&P 500 index fund at 0.41% and the average multi-cap core fund at 0.97% (0.46% counting ETFs only), citing Lipper data as of December 31, 2025. Whatever separates VOO from VTI, it is not the fee.

VOO vs VTI returns: what the record shows

Average annual returns at net asset value through September 30, 2026, from the same fact sheets (year to date is cumulative):

VOO came out ahead in every period, by 0.14 to 1.19 percentage points a year. Since the two funds share most of their holdings, the gap comes almost entirely from the smaller companies VTI adds: over this stretch they returned less than the giants and pulled VTI's average down a little. Small gaps compound. At Vanguard's published 10-year averages, $10,000 would have grown to about $41,500 in VOO and about $39,400 in VTI, before taxes and with dividends reinvested, as the figures assume.

Two traps worth knowing. First, do not compare the since-inception numbers (14.94% for VOO, 9.44% for VTI). VTI's clock started in May 2001 and VOO's in September 2010, so VTI's figure includes the 2001 to 2002 bear market and 2008, and VOO's includes neither. Compare matching periods only. Second, past performance is not a guarantee of future results, and that line is not boilerplate here. The entire difference between these funds is whether the biggest companies keep outrunning everyone else, and nobody knows that in advance.

On volatility, Vanguard's three-year standard deviation is 12.43% for VOO and 12.84% for VTI. Slightly bumpier, which fits Vanguard's own note that mid and small cap ETFs often fluctuate more than large cap ones.

Why the sector tables do not line up

Put the two fact sheets side by side and VTI looks more tech-heavy: 43.1% Technology against VOO's 39.7% Information Technology. Most of that is labeling. VOO's sectors use the GICS system, which puts Alphabet and Meta in Communication Services (9.9% of VOO). VTI's use the ICB system, which counts them as Technology, and leaves a Telecommunications bucket of just 2.1%. Different rulebooks, same companies. Do not compare those two tables row by row.

Watching VOO and VTI side by side

On a normal day the two move almost in step. The days they pull apart are the days small and mid caps go one way and the giants go another, and that is easy to miss in a phone app that shows one quote at a time. Add VOO and VTI to your list in MarketCast and the Stream plays them full screen on your TV, alongside the indexes, the day's movers and headlines, with a ticker tape along the bottom. The free version shows delayed prices and is supported by commercials. Premium is the real-time data package, and it adds the Stock Wall, the S&P 500 as a grid of tiles colored by how each stock is moving, which for a VOO holder is a fairly literal picture of what you own.

So, VOO or VTI?

We are not going to answer that. What we can do is lay out the questions the choice turns on. Do you want the 500 largest US companies, or the whole market including a few thousand smaller ones at about a tenth of the weight? Do you already own other funds that cover mid and small caps? Some investors pair an S&P 500 fund with a separate small and mid cap fund, which ends up looking a lot like VTI in pieces. Does your workplace plan offer only one of the two as a mutual fund? Those are your questions, not ours.

If the comparison you are really weighing is the S&P 500 against the Nasdaq-100, our post on VOO vs QQQ walks through that one, and the concentration story there is much bigger.

To say it plainly: this article explains how two funds differ. It is not investment advice and not a recommendation to buy, sell or hold either one. Fund figures change every quarter, so check the current fact sheets and prospectuses on vanguard.com, and if you are deciding with real money, talk to a licensed financial advisor who knows your situation.

Keep the market on in the background

Whichever funds you hold, it helps to see them without opening a brokerage app ten times a day. MarketCast is free to download on Fire TV, Google TV, Android TV and Apple TV, and its Stream puts them full screen on your TV: your stocks and funds, the indexes, movers and headlines, playing on their own. Our guide to watching your portfolio on TV shows how to set up your list, the supported devices page lists what it runs on, and if a quote on the TV ever looks different from your broker's, here is why stock prices differ between apps.