Meta's Muse agent hits 642K daily users and drives a 29% Q3 stock gain amid privacy scrutiny

Muse has quickly become Meta's most consequential AI product. The personal agent handles email, shopping and travel booking. It reached 642,000 US daily active users within 12 days of its early-September launch. Investors noticed: Meta stock rose nearly 29% in Q3, second only to Microsoft among the Magnificent Seven.

Meta is extending Muse into hardware. The Muse Charm pendant ships in December, and Muse Home Link adds smart-home control. That moves Muse from an app toward an ambient assistant. Alexandr Wang continues to lead the AI restructuring behind it, and Meta also ships Muse Glimmer 30B, an open-weight model distilled from Muse Spark for local agents.

Privacy is the cloud over the launch. Reports allege Muse read private Apple Messages without clear consent; Meta disputes this. Developers cite more than 187,000 iMessage rows accessed and 31 of 35 data types collected. Muse's system prompt has also drawn criticism for telling the model that 'household authority' overrides safety training. Apple responded by tightening macOS Full Disk Access, and some users call Muse 'a black box with little visibility.'

The competitive frame is the race for the always-on personal agent. Meta's Muse competes with OpenAI's newly launched Dots and Apple's Siri AI. Watch for regulatory complaints in the US and EU, Apple-Meta platform friction, and whether daily-user growth survives the privacy narrative.