Mark Zuckerberg’s net worth swung by more than $18 billion twice this summer, once rising and once falling, as Meta Platforms’ AI spending divided Wall Street. A blowout earnings report sent Meta’s stock to record highs near $780 and added roughly $26.8 billion to Zuckerberg’s net worth in a single day, as investors cheered surging revenue and his pitch to build “personal superintelligence” for everyone. The reversal came when Meta guided capital expenditures toward as much as $145 billion this year, up from around $72 billion in 2025, flipping the mood and causing the stock’s worst day of the year, dropping Zuckerberg’s fortune roughly $18 billion. Revenue still climbed 28% from a year earlier last quarter, but free cash flow nearly vanished as spending on chips, servers, and data centers ballooned. Some investors see visionary empire-building; others see a company pouring almost every dollar it earns into an unproven future. The whipsaw indicates the market has reached no consensus on whether the AI build-out will pay off. Zuckerberg has a history of costly bets that critics mocked before they worked, but returns may take years to appear, if at all. Meta is now one of the largest AI-infrastructure bets in the market, and owning it means accepting sharp swings and a long time horizon.