David Rosenberg warns US stock market resembles bubble

David Rosenberg: David Rosenberg is the founder and president of Toronto-based Rosenberg Research & Associates Inc., where he provides macroeconomic analysis and investment strategy commentary. In mid-October 2026, he warned that the U.S. stock market increasingly resembles a bubble due to extreme valuations, leverage, and investor positioning not seen in his 40-year career, with the rally more dependent on AI advancements than the dot-com era. He has positioned his portfolios toward Treasuries and overseas equities, viewing the U.S. as the epicenter of an overpriced technology boom. Sector Focus: The current bull market shows greater reliance on artificial intelligence developments compared to prior technology-driven rallies. Market Concerns: Recent commentary highlights fragilities in the U.S. economy alongside stretched market conditions and divergences across asset classes. Investment Trends: Some portfolio managers have shifted allocations toward government bonds and international equities amid concerns over domestic market imbalances.