Is Buying a Single S&P 500 ETF Enough for Your Portfolio?

Source Motley_fool

Key Points

  • S&P 500 index funds, such as the Vanguard S&P 500 ETF (VOO), hold trillions of dollars in investor money.

  • Despite their popularity, they invest only in U.S. large-cap stocks, leaving other asset classes underrepresented in many portfolios.

  • An S&P 500 fund alone is enough for a long-term investing strategy, but diversifying to other asset classes is a better idea.

  • 10 stocks we like better than Vanguard S&P 500 ETF ›

Most people equate investing in "the market" with the S&P 500 (SNPINDEX: ^GSPC). It's one of the best-known indexes in the world. The three biggest ETFs in the world are based on it. For a lot of people, it's pretty much the only thing they have in their portfolio.

But is it enough?

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Using an S&P 500 fund, such as the Vanguard S&P 500 ETF (NYSEMKT: VOO), is a logical and defensible choice to use as the core of your portfolio. It contains the largest, most successful, and most durable companies in the world.

Coins, bars, arrows, and "S&P 500."

Image source: Getty Images.

But it also includes just 500 U.S. large-cap stocks. Among the things that are left out if you only invest in the S&P 500:

  • Small-cap stocks.
  • International stocks.
  • Bonds.
  • Gold.
  • Cryptocurrencies.
  • Commodities.

That's a lot of diversification, risk mitigation, and return potential that's being left on the table. It's easy to focus solely on the S&P 500, which has been one of the best-performing asset classes for years. But performance across asset classes moves in cycles. Small-caps and international stocks, for example, have historical periods where they've outperformed U.S. large-caps for years. I don't think you want to ignore that altogether.

Can a portfolio consisting of just one S&P 500 ETF be enough? It can. And it's certainly better than keeping your money in a bank account for years or not saving at all.

Could a more diversified portfolio be better? I think so. The long-term performance difference may not be huge, but its ability to smooth volatility, deliver returns from different sources, and potentially outperform the S&P 500 over time shouldn't be discounted.

Should you buy stock in Vanguard S&P 500 ETF right now?

Before you buy stock in Vanguard S&P 500 ETF, consider this:

The Motley Fool Stock Advisor analyst team just identified what they believe are the 10 best stocks for investors to buy now… and Vanguard S&P 500 ETF wasn’t one of them. The 10 stocks that made the cut could produce monster returns in the coming years.

Consider when Netflix made this list on December 17, 2004... if you invested $1,000 at the time of our recommendation, you’d have $387,428!* Or when Nvidia made this list on April 15, 2005... if you invested $1,000 at the time of our recommendation, you’d have $1,221,398!*

Now, it’s worth noting Stock Advisor’s total average return is 895% — a market-crushing outperformance compared to 205% for the S&P 500. Don't miss the latest top 10 list, available with Stock Advisor, and join an investing community built by individual investors for individual investors.

See the 10 stocks »

*Stock Advisor returns as of June 26, 2026.

David Dierking has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Vanguard S&P 500 ETF. The Motley Fool has a disclosure policy.

Disclaimer: For information purposes only. Past performance is not indicative of future results.
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