Anthropic IPO Filing Revives AI Enthusiasm; Chip Stocks Rally, Philadelphia Semiconductor Index Jumps 2.8%

U.S. major indexes closed higher Monday as Anthropic's public IPO filing reignited AI investment enthusiasm and falling oil prices eased inflation concerns. The Dow rose 146.42 points, or 0.28%, to 52,361.58. The S&P 500 gained 0.70% to 7,676.77, ending a two-day losing streak. The Nasdaq added 0.83% to 26,169.38, and the Philadelphia Semiconductor Index jumped 2.82% to 11,083.47. Claude developer Anthropic filed publicly for an IPO, planning to list on the Nasdaq under the ticker "ANT." The filing showed first-half revenue of $16.29 billion, roughly 13 times the year-earlier figure. Chip stocks led gains: Nvidia (NVDA) rose 2.39%, AMD (AMD) 2.80%, Broadcom (AVGO) 2.33%, Micron (MU) 2.98%, and Western Digital (WDC) 3.63%. Microsoft (MSFT) gained 1.54% after offering voluntary buyouts to about 60,000 employees, roughly 27% of its full-time workforce. Meta (META) fell 1.88% as it plans to raise up to $95 billion in equity to fund AI development. Investors await third-quarter results from 163 S&P 500 companies this week, including Alphabet (GOOGL), Microsoft and Amazon (AMZN), plus Wednesday's Fed rate decision. Futures price a roughly 90% chance of holding rates at 3.75%-4%.