Stock Market Kicks Off Post-Holiday Trading with AI Momentum and Key Corporate Moves

Market Overview - U.S. stock markets resumed normal trading hours on December 26, 2025, following the Christmas holiday, with major indices closing at record highs due to strong AI sector performance and positive economic data [1][3] - The Dow Jones Industrial Average (DJIA) rose 0.6% to 48,731.16, the S&P 500 (SPX) gained 0.3% to 6,932.05, and the Nasdaq Composite (IXIC) increased 0.2% to 23,613.31 [3] Premarket Activity - In premarket trading, Dow Jones futures were down approximately 0.1% to 0.2%, while S&P 500 futures showed a fractional decline of 0.03% to 0.1% lower; Nasdaq 100 futures edged slightly higher by 0.00% to 0.02% [4] Corporate Earnings and Developments - Nvidia (NVDA) shares rose 0.6% to 0.7% in premarket trading following the announcement of a $20 billion acquisition of assets from AI chip startup Groq, aimed at strengthening its position in the AI inference sector [8] - Nike (NKE) shares surged 4.6% on December 24, supported by a regulatory filing revealing Apple CEO Tim Cook's $3 million purchase of Nike shares [9] - Micron Technology (MU) shares rose 3.8% on December 24 and continued to gain 2% in premarket trading, contributing to a nearly 22% increase this month due to optimistic earnings forecasts [13] - Dynavax Technologies Corp. (DVAX) shares soared 38.2% after Sanofi announced its acquisition of the company for approximately $2.2 billion [13] - Intel Corp. (INTC) shares fell 0.5% after reports that Nvidia has ceased testing its 18A production process with Intel [13] - Snowflake (SNOW) is reportedly in advanced discussions to acquire AI-native startup Observe for around $1 billion, which would be its largest acquisition to date [13] - Prudential Financial (PRU) shares rebounded after a planned share buyback program of up to $1 billion was announced [13] - Biohaven Pharmaceutical (BHVN) shares dropped 13.4% in premarket trading after its depression drug failed in a clinical trial [13] - DENSO Corporation announced a joint development agreement with MediaTek Inc. to accelerate next-generation automotive system-on-chips [13] - Infineon Technologies achieved a milestone with all global operations now supplied with 100% green electricity [13]