Investing in the Vanguard S&P 500 ETF (VOO)? Beware of This 1 Sneaky Risk.

Investing in the Vanguard S&P 500 ETF (VOO)? Beware of This 1 Sneaky Risk.

Selena Maranjian, The Motley Fool

Sat, September 12, 2026 at 10:20 PM GMT+3 4 min read

If you're investing in the Vanguard S&P 500 ETF (NYSEMKT: VOO) -- or the SPDR S&P 500 ETF (NYSEMKT: SPY) -- that's great. You're now a partial owner of 500 of America's biggest companies.

Even Warren Buffett has recommended low-cost S&P 500 index funds for most of us small investors. In his 2016 letter to shareholders, he noted, "Over the years, I've often been asked for investment advice ... My regular recommendation has been a low-cost S&P 500 index fund."

Missed Nvidia in 2009? This Rare Signal Is Flashing Again. In 2009, a "Double Down" signal flashed for a little-known chipmaker called Nvidia. For the first time in years, that same "Total Conviction" signal is flashing for a company 1/100th the size of Nvidia. Continue »

But there's a bit of a problem with these index funds today: They're quite concentrated. Here's a closer look at this issue, along with a way to invest in the S&P 500 -- without the concentration.

What's the problem?

Check out the recent top 10 components of the Vanguard S&P 500 ETF:

Data: Vanguard.com, as of July 31, 2026.

See anything interesting? The top 10 holdings make up fully 38% of the fund's total value. And the top three holdings make up a whopping 20%. So yes, you'll own a bit of 500 different companies with this fund, but the lion's share of your money will be in relatively few of them. That's good and bad.

It's good because this is a market cap-weighted fund, with larger companies holding more sway than smaller ones. And the biggest ones are the ones that have grown the most. Nvidia has averaged annual gains of 70% over the past three years.

But if there's a stock market crash or correction, as there invariably is now and then, high-tech stocks often fall harder than their counterparts. That can be OK as long as you have a very long-term investing period. But it's not ideal.

And what if some smaller companies in the index do really well? If one triples in value, you're not going to see much of an effect in the fund's overall value. Here are the weightings of some other well-known companies:

Data: Slickcharts.com, on Sept. 9, 2026.

Clearly, owning some shares of a typical S&P 500 index fund won't be putting much of your money in stocks like these -- even though they can be big growers, too.

Consider this alternative to the S&P 500

If you're now feeling uneasy about the concentration of the Vanguard S&P 500 ETF and similar funds, there's a solid alternative to consider: an equal-weighted fund, such as the Invesco S&P 500 Equal Weight ETF (NYSEMKT: RSP). Its 500 components are rebalanced quarterly, so between rebalancings, you'll see some fluctuation in the weightings as various stocks gain or lose value from day to day and year to year, but overall, their weightings will be quite similar. This permits FedEx and Costco (and hundreds of other companies) to influence the index as much as Nvidia and Apple.

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 are built for long-term growth and 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 $417,413!* Or when Nvidia made this list on April 15, 2005... if you invested $1,000 at the time of our recommendation, you'd have $1,341,294!*

That performance is why people listen. With a track record of beating the S&P 500 by nearly 5x, Stock Advisor offers a distinct advantage. Don't miss the latest top 10 list, available with Stock Advisor, and join an investing community built for the long haul.

See the 10 stocks »

*Stock Advisor returns as of September 12, 2026.

JPMorgan Chase is an advertising partner of Motley Fool Money. Selena Maranjian has positions in Alphabet, Amazon, Apple, Berkshire Hathaway, Broadcom, Costco Wholesale, Meta Platforms, Microsoft, and Nvidia. The Motley Fool has positions in and recommends Alphabet, Amazon, Apple, Berkshire Hathaway, Broadcom, Costco Wholesale, JPMorgan Chase, Meta Platforms, Microsoft, Nvidia, Starbucks, Vanguard S&P 500 ETF, and Walt Disney. The Motley Fool recommends FedEx and recommends the following options: long January 2028 $320 calls on McDonald's and short January 2028 $340 calls on McDonald's. The Motley Fool has a disclosure policy.

Investing in the Vanguard S&P 500 ETF (VOO)? Beware of This 1 Sneaky Risk. was originally published by The Motley Fool