Meta Platforms shares rose 11.3% to $741.25 on Monday as Muse, its personal AI agent, climbed to the top of Apple's App Store and prompted renewed investor optimism over the company's artificial-intelligence spending. The rally added $192 billion to Meta's market capitalization by one calculation and more than $13 billion to CEO Mark Zuckerberg's net worth, while an earlier Benzinga Pro estimate put the intraday market-value increase at about $207.5 billion. Sensor Tower data showed 2.8 million Muse downloads across U.S. and Canadian app stores in its first 12 days, although another account cited 1.8 million downloads over that period. Evercore ISI analyst Mark Mahaney said Muse offers evidence that Meta's more than $200 billion in annualized AI capital and operating spending could support advertising, subscriptions and transaction revenue. AI enthusiasm also pushed AMD up almost 10% and above a $1 trillion market capitalization, while the Nasdaq reached record highs and the Philadelphia Semiconductor Index gained 4.3%. Investors are also focused on Thursday's summit between President Trump and China's Xi Jinping, possible diplomatic engagement with Iran, falling crude prices, French sovereign-debt stress and hawkish signals from Federal Reserve officials.