Stretched S&P 500 valuations may point to late-stage AI boom, strategist says

Published 06/16/2026, 07:03 AM
© Reuters

© Reuters

Investing.com -- The S&P 500's valuation remains deeply stretched when measured against long-run earnings trends, a signal that equity markets may be entering the final, euphoric phase of the artificial intelligence rally, according to Capital Economics.

John Higgins, Chief Economic Adviser at Capital Economics, warned in a note on Tuesday that the index's cyclically adjusted price-to-earnings ratio (known as the CAPE), has risen by more than 12 points since the start of 2023 to above 40, "a level last seen before the dotcom bubble burst."

The CAPE has accounted for just over two-thirds of the S&P 500's rally since early 2023, which Capital Economics broadly identifies as the starting point of the AI-driven advance. 

Higgins said this is "one sign that we may be in the 'blow-off' phase of the AI-fuelled rally."

He added that the picture looks less alarming through a conventional lens. The forward 12-month price-to-earnings ratio has risen by fewer than four points and currently sits around 21, well below its dotcom-era peak above 24. 

The forward three-year ratio has contributed only about 13% to the rally and stands near 17, compared to a dotcom peak above 22.

Capital Economics noted that it is inclined to weight the CAPE more heavily, citing skepticism that recent exceptional earnings-per-share growth is sustainable, elevated capital spending on technology relative to GDP, and a near-record ratio of equity market value to net worth in the U.S. nonfinancial corporate sector as its three concerns.

Higgins also noted that excess CAPE yield has historically been a reliable indicator of long-run equity returns relative to Treasuries, and the current reading points to below-average excess returns over the coming decade.

Latest comments

Ai will break 😢
pro badge
No shit Sherlock!! Ridiculous pricing. Humans can't possibly be trading anything anymore. Look at the daily gains. I've never witnessed FOMO on overpriced tech stocks in my life. Elon Musk. The wizard of Wall Street. His new money losing shit offering that loses billions every year and only grosses 18 billion is worth trillions???
Risk Disclosure: Trading in financial instruments and/or cryptocurrencies involves high risks including the risk of losing some, or all, of your investment amount, and may not be suitable for all investors. Prices of cryptocurrencies are extremely volatile and may be affected by external factors such as financial, regulatory or political events. Trading on margin increases the financial risks.
Before deciding to trade in financial instrument or cryptocurrencies you should be fully informed of the risks and costs associated with trading the financial markets, carefully consider your investment objectives, level of experience, and risk appetite, and seek professional advice where needed.
Fusion Media would like to remind you that the data contained in this website is not necessarily real-time nor accurate. The data and prices on the website are not necessarily provided by any market or exchange, but may be provided by market makers, and so prices may not be accurate and may differ from the actual price at any given market, meaning prices are indicative and not appropriate for trading purposes. Fusion Media and any provider of the data contained in this website will not accept liability for any loss or damage as a result of your trading, or your reliance on the information contained within this website.
It is prohibited to use, store, reproduce, display, modify, transmit or distribute the data contained in this website without the explicit prior written permission of Fusion Media and/or the data provider. All intellectual property rights are reserved by the providers and/or the exchange providing the data contained in this website.
Fusion Media may be compensated by the advertisers that appear on the website, based on your interaction with the advertisements or advertisers.
© 2007-2026 - Fusion Media Limited. All Rights Reserved.