Rob Isbitts
Fri, April 24, 2026 at 9:32 AM CDT

There’s a well-known comedian who likes to say, “I don’t know it for a fact, I just know it's true.” Well, if you’ve been thinking as I have that the influence of artificial intelligence (AI) on the S&P 500 Index ($SPX) has become too big to ignore, now you know it's true.

As a recent analysis by Goldman Sachs concluded, AI-linked companies have jumped from just 25% of the index in late 2022 (when ChatGPT launched) to 45% now. Let’s be clear: 45% of the S&P 500 now has its fate tied to AI. The spend, the ROI potential, the spoils, and the risks. Let that sink in.

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With the index having morphed from the Magnificent 7 to the broader AI pie, we should consider what this means to all of the 11 sectors of the S&P 500. Perhaps most or all businesses will be AI-aligned in some way, shape, or form soon. It is becoming that ubiquitous.

But my question is this: does it create even more of a feast-or-famine situation for investors when looking across sectors? I’m a risk manager first, and I can’t help but think that yet another assumed investing ritual that has worked for the past century is now at risk of becoming a dinosaur. Right before our eyes.

The sector allocation of the S&P 500 ETF (SPY), as of March 31, is largely tech and a handful of supporting players. There are also several sectors that barely matter in the grand scheme of things. They do not occupy enough space within the index to carry any meaningful influence.


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Here is the impact across the board.

These three sectors now house the vast majority of the index’s most elite businesses, including most of the Mag 7. With tech alone making up over 33% of the index, and the three sectors having a majority vote (if this were Congress, which thankfully it isn’t), the correlation between these sectors and the broader S&P 500 is nearly 1:1.

For investors, this means that "diversifying" across these three sectors no longer provides safety; it simply doubles down on the same AI-driven momentum. If the AI hardware cycle pauses, these three sectors act as a single, massive weight on the index.