Meta shares drop 7.22% as Anthropic launches rival Claude Duet AI agent

Meta Platforms shares dropped 7.22% following Anthropic's launch of Claude Duet, a proactive personal artificial intelligence agent that directly challenges Meta's Muse assistant. Claude Duet, powered by Anthropic's Opus 5.5 model, was developed by a former Meta product manager and launched as a research preview for Pro and Max subscribers. Meta faces rising rivalry despite strong reach, with Muse already logging over 14 million installs and more than 10 million active users in the U.S. and Canada. However, mounting AI competition comes amid heavy infrastructure spending, with Meta projecting 2026 capital expenditures of $135 billion to $145 billion.