How the Top S&P 500 Companies Have Changed Over Time

In this graphic, we show the top S&P 500 companies over the past several decades to see how the index has evolved over time.

Data and Key Takeaways

The data we used to create this graphic was sourced from Goldman Sachs’ Global Strategy Paper (September 2024 edition). All figures are as of December 31st.

Starting with 1990, the three biggest companies on the S&P 500 were IBM, Exxon Mobil, and General Electric.

Company	% of Index
IBM	2.9
Exxon Mobil	2.9
General Electric	2.3
Philip Morris	2.2
Royal Dutch Shell	1.9
Bristol-Myers Squibb	1.6
Merck & Co	1.6
Walmart	1.6
AT&T	1.5
Coca-Cola	1.4

IBM dominated the tech space in 1990 with its leadership in computers and enterprise systems. Today’s IBM is quite a different business, with a focus on cybersecurity, cloud computing, and artificial intelligence.

Moving forward to 2000, IBM has fallen out of the top 10, replaced by other rising tech companies in Cisco Systems, Microsoft, and Intel.

Company	% of Index
General Electric	4.1
Exxon Mobil	2.6
Pfizer	2.5
Cisco Systems	2.4
Citigroup	2.2
Walmart	2.0
Microsoft	2.0
American International	2.0
Merck & Co	1.8
Intel	1.7

Cisco’s stock experienced a massive rally in the late 1990s (as did many other tech stocks), reaching a peak of $79.37 per share in 2000. The company’s shares have never reached this point since.

Next, in 2010, Exxon Mobil became the biggest constituent on the S&P 500. The company benefited from rising energy demand and increasing oil prices following the 2008 financial crisis.

Company	% of Index
Exxon Mobil	3.2
Apple	2.6
Microsoft	1.8
General Electric	1.7
Chevron	1.6
IBM	1.6
Procter & Gamble	1.6
AT&T	1.5
Johnson & Johnson	1.5
JPMorgan Chase	1.5

Note that Chevron, another major oil producer, also made it into the top 10 in this year.

Lastly, we look at the top 10 stocks of 2024 (the exact date of these numbers was not specified in the source material).

Company	% of Index
Apple	7.0
Nvidia	6.4
Microsoft	6.4
Alphabet	6.2
Amazon	3.8
Meta	2.4
Eli Lilly	1.8
Broadcom	1.6
Tesla	1.4
JPMorgan Chase	1.2

We can see how today’s tech giants have come to dominate the S&P 500 by looking at their relatively high percentage share of the index. The reason for this is that the S&P 500 is a capitalization weighted index, meaning stocks with higher market caps carry greater weight.

For investors who dislike this method, S&P offers an equal-weighted version of the S&P 500 (EWI) which includes the same constituents, but each is allocated a fixed weight of 0.2%.

Invesco manages the largest ETF tracking the S&P 500 EWI (Ticker: RSP), which has $63.6 billion in assets under management.

Source: Visual Capitalist