Mark Zuckerberg lost nearly $11 billion on Monday as Meta shares fell amid investor concerns about the company’s AI spending, extending a two-day selloff that has reduced his fortune by $19 billion to below $250 billion. The decline came despite Meta hiring MongoDB’s CEO to lead an enterprise push. Meta shares had gained around 36% in September before Friday’s drop, supported partly by enthusiasm for its Muse AI assistant, which recorded 2.8 million downloads in its first two weeks. The stock rose 4.5% on Thursday before falling roughly 4% on Friday after Goldman Sachs warned about the scale of AI infrastructure spending. The warning raised broader questions about whether Meta, Microsoft, Alphabet, Amazon and Oracle can generate enough revenue to justify their investments. Investor attention is focused on Meta’s expected capital expenditure of up to $145 billion in 2026 and whether those investments will produce sufficient returns.