Same Issuer, Same Fee — Different Index
VOO and VTI are both managed by Vanguard, both structured as open-end ETFs, and both charge an identical 0.03% expense ratio. They share the same tax advantages, including Vanguard's patented cross-share-class structure that minimizes capital gains distributions. On the surface, they look almost interchangeable.
The key difference is the index each fund tracks. VOO follows the S&P 500 Index, a curated list of approximately 500 large-cap U.S. companies selected by a committee at S&P Dow Jones Indices. VTI follows the CRSP US Total Market Index, which captures virtually every publicly traded U.S. company — roughly 3,600 stocks spanning large, mid, small, and micro-cap segments.
This means VTI includes everything in VOO, plus approximately 3,100 additional smaller companies. For a deeper look at what VOO holds and how the S&P 500 is constructed, see our complete guide to the Vanguard S&P 500 ETF.
There's also an important philosophical difference between the two indexes. The S&P 500 is actively curated — a committee decides which companies qualify based on profitability, liquidity, and sector balance. This means the S&P 500 is not a purely passive index; it contains a layer of human judgment. The CRSP US Total Market Index, by contrast, is rules-based and captures virtually every U.S. stock above a minimum liquidity threshold. If you believe in pure passive investing with minimal human intervention, VTI aligns more closely with that philosophy.
Holdings Overlap: 85% the Same Fund
This is the most important fact in the VOO vs VTI debate: roughly 85% of VTI's total assets are invested in the same S&P 500 stocks that make up 100% of VOO. The top 10 holdings in both funds are identical — NVIDIA, Apple, Microsoft, Amazon, Alphabet, Broadcom, Meta, Tesla, and Berkshire Hathaway — and they occupy nearly identical weights.
The remaining ~15% of VTI consists of mid-cap stocks (companies ranked roughly 500th to 1,000th by market cap), small-cap stocks (1,000th to 2,000th), and micro-cap stocks (2,000th and smaller). These are companies like Crocs, Duolingo, and Axon Enterprise in the mid-cap range, down to much smaller firms with market caps under $1 billion.
Because of this massive overlap, VOO and VTI move in near-lockstep on most days. Their correlation over the past decade has been approximately 0.99. The practical difference between them is driven entirely by whether that extra 15% of small- and mid-cap stocks outperforms or underperforms the large-cap core.
For investors who want to examine VOO's full holdings and sector breakdown, we maintain a detailed data page with the latest information.
Diversification: Does More Holdings Mean Less Risk?
VTI holds roughly 7 times as many stocks as VOO. Intuitively, more stocks should mean more diversification and therefore less risk. In practice, the benefit is smaller than you might expect.
The S&P 500 already captures about 85% of total U.S. stock market capitalization. Adding the remaining 15% in small- and mid-caps does broaden your exposure, but it doesn't dramatically change the risk profile. Both funds carry the same fundamental risk: U.S. equity market risk. When the market drops, both VOO and VTI drop by nearly the same amount. In 2022, VOO fell -18.19% and VTI fell -19.53% — VTI actually declined more because small-cap stocks suffered steeper losses.
Where VTI's diversification helps is in regime changes. During periods when small-cap stocks lead the market — as they did from 2000 to 2010 after the dot-com bubble burst and mega-cap tech cratered — total market funds outperform large-cap-only funds. Small-cap stocks also tend to recover faster from recessions, which can benefit VTI during the early stages of economic expansions.
The real diversification benefit of VTI isn't about holding more stocks; it's about capturing a different segment of the economy — the fast-growing mid-size companies and the small innovators that haven't yet joined the S&P 500. Some of today's S&P 500 giants (Tesla, for example) were once small-cap stocks that only appeared in total market indexes.
Performance: Large-Cap Dominance vs Small-Cap Cycles
Over the past decade, VOO has outperformed VTI. This is entirely attributable to the dominance of mega-cap technology stocks — Apple, Microsoft, NVIDIA, Amazon, Alphabet, Meta, and Tesla — which collectively account for over 30% of the S&P 500. Because VOO concentrates more weight in these companies (since it excludes the dilutive effect of thousands of smaller stocks), it benefits more when large-cap tech outperforms.
| Period | VOO | VTI | Difference |
|---|---|---|---|
| 2025 | +17.82% | +16.70% | +1.12% VOO |
| 2024 | +24.98% | +23.65% | +1.33% VOO |
| 2023 | +26.32% | +26.03% | +0.29% VOO |
| 2022 | -18.19% | -19.53% | +1.34% VOO |
| 2021 | +28.78% | +25.72% | +3.06% VOO |
| 10Y Ann. | ~13.1% | ~12.4% | ~0.7% VOO |
Returns include dividends. Data as of . Past performance does not guarantee future results. Sources: Vanguard, StockAnalysis.com.
It would be a mistake to extrapolate recent large-cap dominance into the future. Small-cap stocks have historically outperformed large-caps over very long periods (the "small-cap premium" documented in academic finance), though this premium has been weak or negative in recent decades. Market leadership rotates, and periods of large-cap outperformance are often followed by small-cap reversion.
The honest answer: no one knows whether VOO or VTI will deliver better returns over the next 10 or 20 years. The return difference between them has historically been small — typically under 1% per year — and swings in both directions.
One useful way to think about it: choosing VOO over VTI is an implicit bet that large-cap companies will continue to outperform. Choosing VTI is a bet on "the entire market" — including the possibility that today's small-caps will become tomorrow's large-caps. Neither bet is unreasonable, and the magnitude of the difference is small enough that other portfolio decisions (like asset allocation between stocks and bonds, or tax-loss harvesting) will likely have a much larger impact on your terminal wealth. You can model specific time periods with our VOO returns calculator.
Fees, Structure, and Tax Efficiency
This is the one comparison category where there is genuinely no difference. Both funds charge 0.03% annually. Both are open-end ETFs managed by Vanguard. Both benefit from Vanguard's patented cross-share-class tax structure, which uses capital losses from the companion mutual fund share class to shield ETF shareholders from taxable capital gains distributions.
Both funds are share classes of larger Vanguard mutual funds: VOO is a share class of the Vanguard 500 Index Fund (VFIAX), and VTI is a share class of the Vanguard Total Stock Market Index Fund (VTSAX). This gives both ETFs the same structural tax advantages. Neither fund has distributed a taxable capital gain in years.
VOO trades roughly 14.5 million shares per day; VTI trades about 3.5 million. Both have tight bid-ask spreads that round to effectively zero for retail-sized orders. Unless you're moving institutional blocks of capital, liquidity is a non-factor in this comparison.
One subtle difference worth noting: VTI tracks the CRSP US Total Market Index, while VOO tracks the S&P 500 Index. Index licensing fees are built into each fund's expense ratio, but CRSP indexes generally cost less to license than S&P indexes. Vanguard moved VTI from the MSCI US Broad Market Index to CRSP in 2013, partly driven by lower licensing costs. The savings are passed through to shareholders, though both funds have converged at the same 0.03% net expense ratio.
If you're considering setting up regular investments, our step-by-step guide to buying VOO covers the process for most major brokerages.
Sector Exposure: Where They Differ
Because VTI includes mid- and small-cap companies that VOO excludes, their sector allocations differ slightly. Small-cap companies are more heavily represented in sectors like industrials, financials, real estate, and healthcare (particularly biotech), while large-cap stocks dominate technology and communication services.
In VOO, the technology sector accounts for approximately 33% of the fund. In VTI, technology's weight drops to roughly 30% because the additional small- and mid-cap stocks dilute the mega-cap tech concentration. Conversely, industrials and real estate carry slightly higher weight in VTI than in VOO.
This means VTI provides marginally more balanced sector exposure, while VOO gives you a larger bet on the technology and communications sectors that have driven U.S. market returns since 2010. Whether that concentration is a benefit or a risk depends on your view of tech's future dominance.
For investors concerned about concentration risk in mega-cap tech — a reasonable concern given that the top 10 stocks now represent over 35% of the S&P 500 — VTI provides a mild natural dilution. It doesn't eliminate tech concentration (those same companies are still VTI's largest holdings), but it softens it slightly by spreading the remaining weight across thousands of non-tech smaller companies. You can see VOO's current sector breakdown in detail on our holdings page.
Which Should You Buy?
Choose VOO if you: want exposure to a precisely defined, universally recognized benchmark (the S&P 500); believe large-cap companies will continue to outperform; want a fund that's easy to explain and widely covered; prefer tighter alignment with the index most financial media references; or are building a portfolio that pairs a large-cap core with dedicated small-cap positions separately.
Choose VTI if you: want comprehensive U.S. market exposure in a single fund; believe in the long-run small-cap premium; prefer maximum diversification across company sizes; want to avoid making active bets on large-cap vs small-cap; or are using a simple buy-and-hold strategy where one fund covers all domestic equity.
One common approach: use VTI as your sole domestic equity fund and pair it with VXUS (Vanguard Total International Stock ETF) for global exposure. This two-fund portfolio covers essentially every publicly traded stock in the world. The alternative is VOO + a dedicated small-cap fund like VB (Vanguard Small-Cap ETF), which gives you more control over your allocation to each segment.
For investors building retirement accounts, both VOO and VTI work well in a Roth IRA or traditional IRA. The tax-advantaged structure of these accounts means you won't pay taxes on dividends or capital gains until withdrawal (or never, in the case of a Roth), so the already-minimal tax efficiency difference between the two funds becomes entirely irrelevant.
Can You Hold Both VOO and VTI?
You can, but you probably shouldn't. Since VOO is a subset of VTI, holding both simply overweights large-cap stocks. If you own $50,000 of VOO and $50,000 of VTI, your portfolio allocates approximately 93% to large-caps and only 7% to mid- and small-caps — less small-cap exposure than VTI alone would give you.
If you want to tilt toward large-caps but still hold some small-caps, a better approach is to hold VTI alone (which already allocates about 85% to large-caps) or to hold VOO alongside a dedicated small-cap fund where you explicitly control the allocation. Combining VOO and VTI just muddies the weighting without giving you any additional diversification benefit.
There's a psychological angle worth considering too. Some investors feel more comfortable owning "the entire market" through VTI — knowing they're not missing out on any segment. Others prefer the clarity and simplicity of the S&P 500 through VOO, a benchmark so widely followed that every financial news outlet reports its daily performance. This isn't a trivial consideration: the investment you understand and feel confident holding is the one you're most likely to stick with through downturns, which matters far more than the marginal return difference between these two funds.
If you're comparing VOO against the SPDR S&P 500 ETF from a fee and structure perspective, our VOO vs SPY comparison covers that in detail.
For a comparison of VOO against a more fundamentally different ETF — one that tracks the Nasdaq-100 instead of the broad market — see our VOO vs QQQ breakdown. Or for a look at how VOO compares to an ETF with a completely different strategy, like dividend income, check VOO vs SCHD.
Frequently Asked Questions
Yes. VTI holds approximately 3,600 stocks spanning large-, mid-, small-, and micro-cap companies across the entire U.S. stock market. VOO holds roughly 500 large-cap stocks from the S&P 500. However, VOO's 500 stocks represent about 85% of total U.S. market capitalization, so the practical diversification difference is smaller than the holdings count suggests.
Yes. The top 10 holdings in VOO and VTI are nearly identical — Apple, Microsoft, NVIDIA, Amazon, Alphabet, Meta, Broadcom, Tesla, and Berkshire Hathaway. The only difference is that each stock's weight is slightly lower in VTI because the total market index includes more stocks in the denominator.
There is little benefit to holding both. VOO's holdings are entirely contained within VTI, so owning both overweights large-cap stocks without adding meaningful diversification. Pick one. If you want total market exposure including small caps, choose VTI. If you want pure large-cap S&P 500 exposure, choose VOO.
Over the past decade, VOO has slightly outperformed VTI because large-cap stocks — particularly mega-cap tech — have dominated U.S. equity returns. However, during periods when small- and mid-cap stocks outperform (as they did in 2000–2010), VTI would have the edge. The historical return difference between them is typically under 0.5% per year.
Yes. Both are excellent core holdings for a Roth IRA. They charge the same 0.03% expense ratio, are highly tax-efficient, and provide broad U.S. equity exposure. Either one can serve as the sole equity holding in a simple retirement portfolio.