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

META surged 6.55% to $653.69 on September 9, 2026, after launching Muse, a personal AI agent that handles shopping, flight booking, and calendar management. The autonomous product marks a potential new revenue channel for the social media giant and could validate its heavy AI spending.

Morgan Stanley pegs the AI agent market at roughly $30 trillion, positioning Muse in a sprawling addressable opportunity. The launch comes as Meta races to monetize its AI infrastructure investments, which have weighed on margins in recent quarters.

Analysts are taking a wait-and-see stance. Despite the rally, sell-side firms recommend holding off on upgrades until Meta reports concrete adoption metrics and revenue contribution from Muse. The caution reflects broader uncertainty around how quickly consumers will pay for AI agents and whether Meta can capture meaningful share in a crowded field that includes startups and Big Tech rivals.

The 6.55% pop suggests traders are pricing in optimism, but the lack of immediate revenue visibility keeps the thesis speculative for now.