AI, the market, and the value of possible worlds
The high valuations of AI stocks are fueling debate over a possible new technology bubble. A few figures explain why. In 2026, Nvidia surpassed a market capitalization of $5 trillion, while the U.S. semiconductor sector posted gains of more than 100% over the past year. The U.S. market is trading at multiples that are very high by historical standards: the S&P 500’s Shiller P/E has risen above 40, levels previously seen only during major episodes of financial euphoria. It is therefore natural to ask whether these prices are sustainable, or whether the market is overestimating the economic impact ...