US tech stocks surged on Monday, with Meta shares jumping 11.43%, adding more than $190 billion to the company's market value in a single session.

The rally came as Meta's new personal AI agent, Muse, rapidly climbed the US app rankings. Launched on September 8, Muse overtook OpenAI's ChatGPT last Friday to become the No. 1 free app on Apple's US App Store, according to Sensor Tower.

Meta describes Muse as "the world's first personal AI agent built for everyone." It can browse the web, fill out forms, manage email and calendars, book reservations and make purchases, while connecting with apps and services that users rely on every day.

The agent can remember users' preferences and handle everyday tasks on their behalf, according to Meta. For sensitive actions involving privacy or payments, it seeks users' approval before proceeding, balancing convenience with security.

Muse's rapid rise marks a significant breakthrough for Meta's push into consumer-facing AI agents after years of investment in the technology. While Meta's AI models have faced stiff competition from leading companies such as OpenAI and Anthropic, the early traction of Muse suggests that the company is making progress in bringing agentic AI into everyday consumer use.

Most AI agents have largely been designed for developers and tech enthusiasts, offering few practical uses for ordinary consumers, but that could be about to change, Bernstein analyst Stacy Rasgon told CNBC on Monday. "Meta's Muse and other agents out there are starting to get more potential for more broad-based adoption."

But the early buzz has not erased market concerns. The tech industry has seen no shortage of AI products that drew huge attention at launch only to lose momentum soon after.

Privacy is another concern. As debates over AI regulation intensify worldwide, Muse's ability to perform cross-platform tasks requires access to large amounts of users' personal data, raising questions about data privacy and security.

Whether Muse is simply a viral hit that fades with time or a product that helps usher AI agents into the mainstream remains to be seen.