The Vickers Top Buyers & Sellers is a daily report that identifies the five companies the largest insider purchase transactions based on the dollar value of the transactions as well as the five companies the largest insider sales transactions based on the dollar value of the transactions.

Vickers Stock Research, a subsidiary of Argus Research Group, tracks and analyzes insider trading and institutional stock ownership trends. Form 13-Fs, which institutions must file to report their holdings, are due 45 days after the end of calendar quarters, and have now come in from 1Q26. We like to review the 13Fs of major activist investors -- including Carl Icahn, Trian Fund Management, Jana Partners, Starboard Value and ValueAct Holdings, among others -- in order to determine their core holdings and new purchases. Activist investing has evolved in recent years and is now less about generating a short-term return on an underpriced stock and more about achieving long-term returns through an active management/investor partnership. Activists have made progress in the past year, with high-profile investments into blue-chip companies such as Fedex and Union Pacific. Here are some recent new purchases and key holdings of activist investors, as well as other high-profile money managers.

Centene is a managed care organization that focuses on government-sponsored healthcare plans, including Medicaid, Medicare, and the individual exchanges. Centene served 20 million medical members as of December 2025, mostly in Medicaid (about 64% of membership), the individual exchanges (about 28%), and Medicare (about 5%). The company also provides Medicare Part D pharmaceutical plans.

Centene is an international healthcare company. Based in St. Louis, Centene offers services to government-sponsored and commercial healthcare providers, with an emphasis on underinsured and uninsured individuals. It is the largest Medicaid managed care organization in the U.S. and a leading provider of insurance under the Affordable Care Act. Its Specialty Services segment provides a range of healthcare products and services to managed care members and other customers.