US Stock Market Outlook (Dec. 21, 2025): S&P 500 Eyes a Santa Rally as Fed Signals, AI Jitters, and GDP Data Shape Year-End Trading
The S&P 500 closed Friday at 6,834.50, the Nasdaq at 23,307.62, and the Dow at 48,134.89, with tech gains lifting indexes to end the week mixed. The S&P 500 is up over 15% in 2025, but December trading has been volatile as investors debate the sustainability of the AI-driven rally and await further signals from the Federal Reserve.