S&P 500 Gains and Losses Today: Huntington Ingalls Stock Sinks as Shipbuilder Cuts Outlook

Market Overview - The S&P 500 dropped 1.9% on October 31, with significant declines in the tech sector due to major firms' spending on AI infrastructure [2][1] - The Dow fell 0.9%, while the Nasdaq experienced the largest decline, plunging 2.8% [2] Company Performance - Huntington Ingalls Industries (HII) shares fell 26.2% after missing quarterly profit estimates and reducing its full-year sales forecast, citing uncertainty with U.S. Navy agreements and labor supply chain issues [3] - Estée Lauder (EL) shares dropped 20.9% after withdrawing its full-year outlook and cutting its dividend, reporting declines in quarterly revenue and organic sales due to weakness in China and Asia travel markets [4] - Aptiv (APTV) shares decreased by 17.7% following production challenges and reduced customer scheduling, although the company is implementing cost-cutting measures [5] - Paycom Software (PAYC) shares surged 21.3% after reporting better-than-expected sales and profits, driven by a strong labor market [6] - Entergy (ETR) shares increased by 15.2% after beating profit estimates and raising its full-year outlook, despite a year-over-year revenue decline [7] - International Paper (IP) shares rose 13.3% after topping profit estimates and announcing a review of strategic options for its global cellulose fibers business [8]