What We Can Learn From the S&P 500

Changes in the S&P 500 are about much more than stock markets.

Let’s take a look.

S&P 500 History

Starting with IBM, each of the top 10 S&P 500 companies can tell a story about the U.S. economy. With IBM, we had the birth of information technology while with Microsoft it matured. Then, we could also cite the Bell Labs subsidiary of AT&T for creating the transistor and the 134 year (or so) rise and fall of GE that takes us back to light bulbs, the first television, jet engines, and so much more. Next, we can cite the role of Big Oil and Big Pharma, and finally tell some consumer stories through General Motors, Coca Cola, P&G, Walmart, Apple, and Amazon. And of course, it all needed the finance that came from firms like Citigroup and JP Morgan.

Together these companies created the fabric of the U.S. economy.

And now that fabric is again shifting with AI.

Our Bottom Line: Economic Growth

Through the GDP, we can see how AI is becoming an increasingly larger presence in our economic lives. In a recent report, the St. Louis Federal Reserve used government data and their own calculations to show why AI contributed a whopping 30% to GDP growth during the 2nd quarter and 11% for the 3rd quarter during 2025.

They looked at what we spent on information processing equipment, software, research and development, and data centers. (I highlighted the 3rd quarter):

And that returns us to our S&P top ten. As the companies that do the vast chunk of AI spending, we can include Nvidia, Microsoft, Amazon, Alphabet, and Meta. Like their S&P top 10 predecessors, they too are now adding to and changing the fabric of the U.S. economy.

My sources and more: Thanks always to Emily Peck at Axios for her daily markets email. From there we looked back at several of the past top 10, here and here. Then, moving to the present, WSJ, here,  here and here, told more about AI spending while the Progressive Policy Institute Heroes 2025 Reports detailed corporate spending. But still, it was the St. Louis Fed that did the best job of connecting AI with the GDP.