ECB Warns AI Bubble Threatens Global Financial Stability
Warnings of an AI bubble have been circulating lately, but a recent blog post from four senior economists at the European Central Bank (ECB) has garnered extra attention. The ECB economists argue that extremely optimistic valuations in the stock market raise questions about whether current prices reflect a rational bet on the transformative technology.
Their analysis concludes that the so-called 'Magnificent Seven' tech giants, which already account for over 35% of the total market cap of the S&P 500 as of October 2025, pose a worldwide structural danger. This is particularly concerning for households investing in index-tracking exchange-traded funds (ETFs), with European household investors estimated to have some $525 billion in exposure to US tech stocks.
The ECB economists also point out that valuations are looking very peaky, with the Cyclically Adjusted Price-to-Earnings (CAPE) ratio on the S&P 500 Index currently at around 41.5-42, close to its all-time high of 44.2 seen in 1999 during the dotcom bubble.
Nicolai Tangen, CEO of Norges Bank Investment Management (NBIM), recently warned that it is 'fairly likely' that the entire value of Norway's $2 trillion Government Pension Fund Global (GPFG) could be lost under current conditions. The ECB economists estimate that an AI industry correction could cost the GPFG 35% of its value.