You own 500 companies

Buying VOO or SPY makes you a partial owner of 500 of America's biggest businesses. It's the default advice for good reason.

Buffett said so himself

In his 2016 shareholder letter, Warren Buffett named a low-cost S&P 500 index fund as his standard answer when people ask him where to put their money.

“My regular recommendation has been a low-cost S&P 500 index fund.”

But it's not that spread out

The top 10 holdings are 38% of the fund. The top three alone are 20%. Most of your money sits in a handful of names, not 500.

“The lion's share of your money will be in relatively few of them.”

Nvidia and Apple run the show

Nvidia is 7.55% of the index and Apple 7.04%, with Microsoft at 5.36% and Amazon at 4.13%, per Vanguard data from July 31, 2026.

The upside of that tilt

Market cap weighting hands the most weight to the biggest winners. Nvidia has averaged 70% annual gains over the past three years.

The downside in a crash

Corrections come around eventually, and high-tech stocks tend to fall harder than the rest. A long time horizon absorbs that, but it still isn't ideal.

Small winners barely move it

Costco is 0.57% of the index, Disney 0.26%, FedEx 0.11%, Dollar Tree 0.03%. If one of them triples, your fund hardly notices.

Equal weight is the fix

A fund like the Invesco S&P 500 Equal Weight ETF (RSP) rebalances quarterly so FedEx and Costco sway the index as much as Nvidia and Apple.