Wall Street firm believes the AI stock market boom is 'nearing an end.' Here's why
A range of equity market bubble indicators show that while the S & P 500 ‘s rally has further to run this year, its medium-term prospects look poor given how frothy the market has become, according to Capital Economics. “Most indicators suggest the AI equity boom is nearing an end,” Capital Economics’ senior market economist James Reilly said Thursday in a note. Capital has been more bullish than most on the stock market since mid-2023, reflecting a view that AI will be a transformative technology. Its year end-2026 S & P 500 forecast has consistently been above consensus. But the firm has also maintained that the AI-driven rally is a bubble that will eventually burst. To assess and spot a late-stage market bubble, Reilly looks at eight indicators including valuations, earnings, index concentration, equity issuance and foreign interest in U.S. equities. Some of those measures are already at or near levels that preceded previous stock market peaks. The analysis shows that while market variables such as earnings expectations look consistent with a market top, others such as volatility and leverage look slightly less alarming. Earnings stand out as the biggest warning sign. Expectations for S & P 500 earnings growth are around levels seen only at the peak of the dot-com bubble, while long-term EPS growth forecasts have surged to a record high. According to Reilly, the heavy concentration of this expected growth in the tech sector means that any signs of weakness in the tech firms’ earnings will weigh heavily on the index. Other indicators are also flashing warning signs. Index concentration is around dot-com-era extremes, net equity issuance has turned positive and foreign ownership of U.S. stocks is at a record high. Reilly said another wave of IPOs and share sales could be particularly significant, since similar issuance booms have historically coincided with market peaks. “On past form, this suggests that the end of the bubble is just months away, rather than years,” he said. Measures of leverage are not yet alarming compared to other factors, though the analyst warns that they are heading in a “concerning direction.” While volatility metrics look consistent with a mid -stage bubble, Reilly notes that constituent -level volatility isn’t as extreme as it was near the end of the dotcom boom. “While we continue to think that the S & P 500 will rally from around 7,650 now to 8,250 by end-2026 , we ultimately forecast it to fall back to 6,500 by end -2027,” he wrote. Those assumptions would equate to 8% upside this year and a 21% slide in 2027.