Vanguard S&P 500 ETF (VOO) and Vanguard Total Stock Market ETF (VTI) are two of the most popular ETFs. Both are low-cost, long-term investment options that have delivered strong historical returns, which is why many investors assume they are basically the same. However, despite their similarities, there are several important differences that can affect diversification, performance, volatility, and long-term growth potential. Using the TipRanks’ ETF Comparison Tool, we have placed VOO and VTI against each other to find out the key differences.
Claim 55% Off TipRanks
Trade AMZN with leverage
Here are three key differences between VOO and VTI that most investors miss.
1. Broader Diversification
VOO gives investors exposure to 500 of the largest U.S. companies by tracking the S&P 500 Index (SPX). It is widely used as a benchmark for the U.S. stock market. Meanwhile, VTI tracks nearly the entire U.S. stock market, including large-, mid-, and small-cap stocks, making it a broadly diversified option for long-term investors.
To be precise, VTI owns 3,473 stocks with total assets of $638.85 billion. Meanwhile, VOO has 507 stocks with $950.87 billion in assets. VTI gives you the same portfolio at the top plus exposure to an extra 3,000 smaller companies that collectively represent 15% of the fund’s value.
The top 10 holdings in both funds are identical — Nvidia (NVDA), Apple (AAPL), Microsoft (MSFT), Amazon (AMZN), Alphabet (GOOGL), Broadcom (AVGO), Meta (META), Tesla (TSLA), and Berkshire Hathaway (BRK.B) — and they occupy nearly identical weights. The real question is whether that bottom 15% — mid and small caps — outperforms or underperforms large caps over your holding period. That single question determines which fund wins.
2. The Concentration Risk
In terms of holdings, VOO is more concentrated at the top compared to VTI. Its top 10 holdings account for 36.5% of total assets, versus 32% for VTI.
That means VOO’s performance is more heavily tied to a small group of mega-cap stocks, particularly large technology companies. VTI still has significant exposure to those same market leaders, but its broader mix of mid- and small-cap stocks slightly reduces concentration risk.
3. Long-Term Returns
Over the past five years, VOO has slightly outperformed VTI. VOO delivered returns of about 71%, compared to roughly 63% for VTI during the same period.
The main reason is VOO’s heavier exposure to mega-cap technology stocks, which have driven much of the market’s gains in recent years. Meanwhile, VTI’s additional exposure to smaller companies slightly reduced overall performance as small- and mid-cap stocks lagged large-cap tech during this period.
Conclusion
Both VOO and VTI are strong, low-cost core ETFs for long-term investors. However, VTI may have a slight long-term advantage because its exposure to small- and mid-cap stocks provides broader diversification and additional growth potential over time.
Meanwhile, VOO offers a simpler and more concentrated approach focused on the largest U.S. companies. That can make it feel slightly more stable and easier to follow, especially for investors who want direct exposure to the biggest market leaders.