Wall Street’s AI obsession has taken over the S&P 500, creating new risks for passive investors
The growing dominance of AI-heavy companies in the S&P 500 means a shrinking circle of tech giants now drives the lion’s share of most investors’ portfolios.
According to JPMorgan data, just 41 AI-related stocks — about 8% of the index — now account for a record 47% of the S&P 500’s total market capitalization. By contrast, the remaining 459 stocks, representing 92% of the index’s constituents, comprise only 53% of its market cap.
The AI-related cohort includes 29 core AI companies such as Nvidia (NVDA), Microsoft (MSFT), Apple (AAPL), Alphabet (GOOGL), and Amazon (AMZN), along with eight AI utilities and four AI capital equipment developers, JPMorgan said.
Macro researcher Jim Bianco attributed much of this concentration to the surge in AI enthusiasm following the release of OpenAI’s ChatGPT nearly three years ago.
Since ChatGPT was released, “these 41 stocks have accounted for 74% of the S&P 500’s total increase. The other 25% came from the remaining 459 stocks,” Bianco wrote.
While the top 41 companies typically represent about half of the index’s market cap, Bianco noted that the current situation is distinct.
“What is different now, however, is that 47% of the index’s capitalization is based on a single theme: AI,” he said. “This is unique and represents the most significant concentration around a single theme ever.”
Opportunity and risk
The runaway success of OpenAI’s ChatGPT has showcased the immense opportunity artificial intelligence offers for productivity and efficiency gains. However, for investors, it also highlights a growing risk: an increasing share of portfolios is being driven by a single growth story that may not sustain its momentum over the long term.
Even average Americans who know little about hyperscalers or AI technology may now have an outsized portion of their financial lives tied to a handful of mega-cap companies.
Kamila Elliott, CEO of Collective Wealth Partners, told CNBC that many retirement savers don’t realize their portfolio performance is largely dependent on just five companies — Nvidia, Microsoft, Apple, Alphabet, and Amazon.
Such concentration undermines diversification, long considered the cornerstone of passive investing. In this environment, Elliott warned, the traditional “set it and forget it” approach may no longer be sufficient.
As InvestorsObserver noted, market concentration risks have been building for some time. In August, Augur Infinity reported that the largest 10% of U.S. stocks now account for more than three-quarters of total market capitalization — a level of concentration not seen since the Great Depression.
Unsurprisingly, those top-tier companies are dominated by the technology sector.