Do the biggest companies in the S&P 500 stay on top?

The top ten in 2000 and what a 26-year holder earned

At the dot-com peak, the ten largest companies were roughly a quarter of the S&P 500. Here's the total return with dividends reinvested from December 31, 1999 to December 31, 2025, with the compound annual return in parentheses:

• Microsoft: up 1,256% (10.6% a year). Still in the top ten, ranked fourth.
• Walmart: up 658% (8.1% a year). Fell out, sits just outside the list.
• Exxon Mobil: up 578% (7.6% a year). Fell out.
• IBM: up 455% (6.8% a year). Fell out.
• Cisco: up 121% (3.1% a year). Fell out.
• Intel: up 58% (1.8% a year). Fell out.
• Citigroup: down 47% (a loss of 2.4% a year). Fell out.
• General Electric, Lucent and AOL: gone, with no continuous 26-year return.
• S&P 500 index for comparison: up 650% (about 8.0% a year).

The companies that didn't survive

General Electric, Lucent and AOL were each broken up or merged away, so no continuous 26-year return exists for a shareholder who held on. Some of the worst outcomes in a concentrated list come from companies that didn't survive in any measurable form.

General Electric was the most valuable company on earth in 2000 and was split into three separate companies by 2024. Lucent collapsed, merged with Alcatel, and is now part of Nokia. AOL merged with Time Warner in 2000. Citigroup nearly failed in the 2008 crisis and took a federal rescue.

How the remaining companies fared

Microsoft, the lone survivor, traded below its December 1999 price for roughly 16 years before its run resumed. Cisco didn't reclaim its 2000 high for more than two decades, and Intel compounded at under 2% a year.

Citigroup never made its shareholders whole. A buyer at the start of 2000 was still down about 47% at the end of 2025, dividends included. Being one of the largest companies in the index didn't guarantee strong returns in the decades that followed.

How concentrated the index is now

In 1999 the top ten were about a quarter of the index. By the end of 2025 they were near 40%, more concentrated than the index had ever been. The same turnover would move a much larger share of a broad-index investor's portfolio.

The ten largest at year-end 2025 were Nvidia (7.3%), Apple (6.5%), Alphabet (6.1%), Microsoft (5.8%), Amazon (4.0%), Meta Platforms (2.7%), Broadcom (2.6%), Tesla (2.4%), Berkshire Hathaway (1.8%) and Eli Lilly (1.5%). Microsoft is the only company on both lists. These companies are named only to illustrate turnover at the top and aren't recommendations.

Today's leaders in a diversified portfolio

No one in 2000 could reliably say Microsoft would thrive while GE, Lucent, AOL and Citigroup faltered. They were all obvious leaders at the time. Concentrating in today's largest companies assumes you can pick the survivors of 2050.

Today's leaders can still belong in a portfolio. The point is to hold them inside something broad enough that the next reshuffle does little damage. A broadly diversified, low-cost portfolio owns new leaders as they emerge.