Grantham Calls AI Biggest U.S. Investment Bubble, Dismisses Bitcoin as 'Unnecessary Nonsense'

During a YouTube interview on Steven Bartlett's "The Diary of a CEO," Jeremy Grantham, co-founder of Boston-based investment firm GMO, called AI the biggest U.S. investment bubble in history and warned of a potential 70% stock market decline. Grantham cited SpaceX as the clearest symbol of speculative excess, saying the company's prospectus will be remembered like the South Sea Bubble.

On bitcoin, Grantham said he owns none and has never owned any, describing it as "an unnecessary piece of nonsense" that does not function as a store of value or convenient medium of exchange. When asked if bitcoin would eventually reach zero, he responded affirmatively, stating it "will certainly go to zero" in the distant future.