Meta stock rockets 9% on Muse Spark AI model launch

Muse Spark is Meta's first model out of its newly formed Meta Superintelligence Lab (MSL), and Wall Street liked what it saw — shares jumped over 9% on the day of the announcement.

Zuckerberg pitched it as a "world-class assistant" with particular strength in visual understanding, health, social content, shopping, and games — squarely aimed at Meta's core products. Notably, unlike Meta's Llama line, Muse Spark is closed source. The company says future versions may go open — but no promises.

The launch signals a strategic pivot: Meta is no longer just the open-source AI underdog. With $115B–$135B planned AI capex in 2026, they're betting the balance sheet on winning the assistant race head-to-head against OpenAI and Google.

Why it matters: Meta just proved it can move markets with a model drop — and going closed-source is a loud signal that they're playing to win, not just contribute.