Jeremy Grantham, a prominent value investor and co-founder of GMO, has issued a warning regarding a potential major decline in U.S. stocks, describing the current market as being in 'super bubble' territory. In recent interviews, Grantham emphasized that as U.S. stock prices continue to rise, the impending downturn could be severe. He predicts that non-U.S. markets may outperform American stocks over the next five to ten years. Grantham's previous forecasts have included a 50% drop in stocks for 2023, despite the S&P 500 finishing the year with a 24% gain. He noted that the U.S. markets are currently under pressure from high valuations, fatigue surrounding artificial intelligence, and political volatility. Additionally, a top fund manager has warned of a potential multi-year bear market, marking a significant momentum shift in the market landscape.