Reston, Virginia-based Leidos Holdings, Inc. (LDOS) is a major U.S. defense, aviation, and technology solutions provider serving government and commercial clients. Its operations span national security, digital modernization, healthcare systems, and advanced engineering. Commanding a market cap of $23.6 billion, the company is known for its large federal contracts, particularly with the Department of Defense, intelligence agencies, and civilian government bodies. Companies worth$10 billion or more are g ...