Centene Corporation withdrew its 2025 earnings guidance following an early analysis of data from the Affordable Care Act (ACA) marketplace that revealed higher morbidity rates and slower growth than anticipated. This led to a reduction in net risk adjustment revenue by approximately $1.8 billion, resulting in an estimated $2.75 per share earnings hit. The health insurer's shares plunged sharply, falling as much as 40% at one point, marking their largest single-day drop since 2006 and closing at an eight-year low. The revenue pressure primarily stemmed from Centene's ACA marketplace plans, with slower growth observed across 22 states. The withdrawal of guidance also triggered downgrades from Wall Street analysts, including JPMorgan, which lowered its rating on Centene shares from overweight to neutral and cut its price target from $75 to $48. The selloff extended to other managed care stocks such as Humana, Cigna, Oscar Health, and Molina Healthcare, which declined in sympathy. Centene's Medicaid business and rising healthcare costs have also been cited as ongoing challenges contributing to the company's financial difficulties.