Meta Platforms shares rallied after the September 8 U.S. launch of Muse, its personal AI agent, adding $13.7 billion to co-founder Mark Zuckerberg's wealth and taking his net worth to $232 billion, according to the Bloomberg Billionaires Index. Muse reached as high as No. 3 on the U.S. App Store on its second day, with early usage running at 10 times the training-phase cohort level. JPMorgan upgraded Meta to Overweight from Neutral and lifted its December 2027 target to $820 from $640, while China Merchants Securities International retained a Buy rating and an $830 target and Morgan Stanley maintained an Overweight rating with a $775 target. Muse is free to use in the United States through iOS, Android and the web, with $20 and $100 monthly subscription plans for additional services. The agent can handle cross-application tasks and continues operating after apps are closed, although purchases and sensitive-information requests require confirmation. Analysts see Meta's distribution through Facebook, Instagram, Messenger and WhatsApp as its main advantage, but Morgan Stanley said further re-rating depends on evidence of sustained adoption and monetizable behavior. Separately, MediaTek posted record August revenue of NT$64.183 billion but its shares fell 2.44% amid a broader Taiwan market selloff.