Stock Market Today, Sept. 9: Meta Surges Over 6.5% on Muse AI Agent Launch

Meta Platforms surged 6.55% to $653.69 on September 9, 2026, following the launch of Muse, its new personal AI agent capable of shopping, booking flights, and organizing calendars. The autonomous product could unlock new revenue streams and validate Meta's substantial AI investments. Morgan Stanley estimates the AI agent market could be worth around $30 trillion. However, analysts recommend waiting for concrete adoption and revenue data before reassessing the stock.