Microsoft announced new AI upgrades across its Microsoft 365 suite on November 18, 2025, as the company seeks to maximize value from its substantial AI infrastructure investments. Charles Lamanna, Microsoft's President of Business Apps and Agents, highlighted the rollout during the company's Ignite conference. Despite the positive product announcement, MSFT stock closed at $493.79, down 2.70% on November 18. This decline reflects the broader market selloff, with the S&P 500 notching its fourth consecutive day of losses—its longest losing streak since August. The tech sector faced particular pressure, with concerns emerging about AI economics and potential overinvestment in the sector.