Anthropic IPO Filing Lifts AI Stocks; Nasdaq Gains 0.83%, Philadelphia Semiconductor Index Rises 2.8%

U.S. stocks closed higher on Monday as Anthropic's initial public offering filing boosted AI-related shares, with semiconductor and optical communications stocks leading gains. The S&P 500 and Nasdaq rebounded from a recent slide ahead of a heavy week of Big Tech earnings, a Federal Reserve rate decision and key economic data. The Dow Jones Industrial Average rose 146.42 points, or 0.28%, to 52,361.58. The S&P 500 gained 53.09 points, or 0.70%, to 7,676.77, and the Nasdaq Composite added 214.04 points, or 0.83%, to 26,169.38. Volume on U.S. exchanges was 16.7 billion shares, below the 17.2 billion average over the prior 20 sessions. Anthropic's filing showed rapid revenue growth alongside substantial losses. The Philadelphia Semiconductor Index rose 2.8% but remains down 12.2% for the month. Lumentum and Coherent gained about 8% and 6%, respectively. Tesla rose 5.2% after Barclays upgraded the stock to "overweight" from "neutral." Meta fell 1.9% after announcing plans to raise up to $95 billion through equity financing to fund AI infrastructure.