Market Indexes Rise on Microsoft Momentum

Markets rallied on May 28, 2026 as investors focused on AI-related corporate developments rather than escalating U.S.-Iran hostilities. The Nasdaq Composite climbed about 0.8% and the S&P 500 rose roughly 0.6%, led by a 3.4% surge in Microsoft after reports it will unveil proprietary AI models and following a large Pentagon-related licensing deal aided by Dell. Arm Holdings jumped sharply (~13.5%), amplifying tech-led index gains, while Caterpillar’s ~1.7% drop weighed on the Dow. Oil and gold barely moved, and U.S. fuel prices eased, signaling that markets prioritized concrete business catalysts over geopolitical noise.