Is VOO too concentrated in technology stocks?

That depends on your definition of too concentrated. The technology sector accounts for approximately 33% of VOO as of early 2026. This is not a deliberate tilt by Vanguard; it reflects the market capitalization of the underlying S&P 500 companies. If tech outperforms, VOO benefits more than an equal-weight index would. If tech underperforms, VOO feels the drag more. Investors who want less tech exposure relative to the market may look at equal-weight S&P 500 funds or sector-diversified alternatives.

How much does a single stock like NVIDIA affect VOO?

With NVIDIA at approximately 7.31% of VOO as of early 2026, a 10% move in NVIDIA's stock translates to roughly a 0.73% move in VOO, all else equal. That is a meaningful single-stock contribution for a fund that holds 518 companies. Apple at 6.63% and Microsoft at 4.95% have similar leverage on any given day. The effect is largest for the top 5 holdings, which together account for roughly 26% of the fund.

Has VOO always been this concentrated in mega-cap tech?

No. When VOO launched in September 2010, the S&P 500's largest component was Exxon Mobil, and the top 10 collectively represented roughly 20% of the index. Technology was a smaller share of total U.S. market capitalization. The shift toward mega-cap tech concentration accelerated between 2015 and 2025 as companies like Apple, Microsoft, and NVIDIA grew dramatically in market value relative to the broader economy. NVIDIA was not in VOO's top 10 as recently as 2022; by early 2026 it had become the fund's single largest holding.

How Concentrated Is VOO? Understanding the Top 10 Holdings

Q: What are VOO's top 10 holdings?

As of February 28, 2026, VOO's top 10 holdings are NVIDIA (7.31%), Apple (6.63%), Microsoft (4.95%), Amazon (3.47%), Alphabet Class A (3.08%), Broadcom (2.56%), Alphabet Class C (2.46%), Meta Platforms (2.40%), Tesla (1.92%), and Berkshire Hathaway (1.57%). Together they represent approximately 36.35% of the fund. The full current list is on the VOO holdings page at voo.us/holdings/.

Ten Stocks, More Than a Third of the Fund

VOO holds approximately 518 companies. Its top 10 account for roughly 36.35% of the entire fund. That gap between 518 names and 10 names controlling more than a third of the portfolio surprises many investors who buy VOO precisely because they want broad diversification. The explanation is market-cap weighting: every company in VOO is held in proportion to its total market value relative to the rest of the S&P 500. Bigger companies own a bigger slice. There is no cap on how large any single holding can grow as long as it remains in the index.

As of February 28, 2026, the top 10 holdings are NVIDIA (7.31%), Apple (6.63%), Microsoft (4.95%), Amazon (3.47%), Alphabet Class A (3.08%), Broadcom (2.56%), Alphabet Class C (2.46%), Meta Platforms (2.40%), Tesla (1.92%), and Berkshire Hathaway (1.57%). Eight of those ten are technology or technology-adjacent companies. The full breakdown by weight is on the VOO holdings page.

How the Top 10 Changed Since 2010

When VOO launched in September 2010, the S&P 500's largest component was Exxon Mobil, which held roughly 3.5% of the index. The top 10 collectively represented about 20% of the fund. Apple was rising fast but had not yet overtaken Exxon. NVIDIA was a mid-cap semiconductor company barely visible in the index. For a fuller picture of what VOO is and how it tracks the S&P 500, that page explains the structure in detail.

The shift from energy-and-finance dominance to mega-cap tech dominance accelerated between 2015 and 2025. Apple overtook Exxon around 2012 and held the top spot for most of the following decade. Microsoft climbed steadily as cloud revenue scaled. Then NVIDIA's AI-driven run redefined the rankings entirely. NVIDIA was not in VOO's top 10 as recently as 2022; by early 2026 it had become the fund's single largest holding at 7.31%. In 2023, the seven largest S&P 500 companies by market cap drove more than half of the index's total return for the year, a degree of concentration not seen since the late 1990s tech bubble.

What Concentration Means in Practice

Concentration is a double-edged feature, not a flaw. With NVIDIA at 7.31% of VOO, a 10% move in NVIDIA's stock translates to roughly a 0.73% move in VOO, all else equal. Apple at 6.63% and Microsoft at 4.95% carry similar leverage on any given trading day. That is the same mechanism that allowed VOO to gain significantly during the AI-driven surge in NVDA shares -- and the same mechanism that deepened the fund's 2022 drawdown as interest rates rose and growth stocks sold off. VOO fell approximately 19% for calendar year 2022, with the technology concentration amplifying losses relative to an equal-weight version of the index.

For investors who find the tech weighting uncomfortable, a direct comparison worth reading is VOO vs QQQ, which shows what even heavier Nasdaq-100 concentration looks like in practice. QQQ's top 10 account for roughly 50% of that fund, making it considerably more sensitive to individual mega-cap moves than VOO. The VOO past performance calculator lets you model what historical concentration meant for specific time periods you may have held, or plan to hold, the fund.

The Bottom Line

More than 64% of VOO is still spread across approximately 508 companies outside the top 10. The fund holds every sector, from energy and utilities to healthcare and consumer staples. Concentration at the top is a structural outcome of how market-cap weighting works, not a portfolio management decision. It means VOO's performance is more sensitive to a handful of large companies than the headline "518 holdings" number implies. That is worth understanding before assuming broad diversification means equal diversification.

Note: holdings data referenced in this guide reflects Vanguard's Feb 28, 2026 disclosure. See the holdings page for the most current breakdown. For current VOO price see the ticker bar above. For current holdings and dividend data see /holdings/ and /dividend/. Verify all data at investor.vanguard.com before making investment decisions. Nothing in this guide is investment advice.