Gilead Sciences Inc. (NASDAQ: GILD)

Gilead Sciences is a biotech giant best known for revolutionizing the treatment of HIV and hepatitis C. Annual revenue is about $27 billion. The company's HIV franchise (Biktarvy, Descovy, Truvada) generates over $18 billion annually and dominates the market. Gilead also developed remdesivir (Veklury), which became a key COVID-19 treatment. The company has been diversifying into oncology through acquisitions, most notably the $21 billion purchase of Immunomedics in 2020.

Pharmaceutical sales drive virtually all revenue, with HIV treatment and prevention accounting for roughly 70%. Hepatitis C (Sovaldi, Harvoni) was once a massive revenue driver but has declined as the curable disease shrinks the patient pool. Oncology (Trodelvy from the Immunomedics acquisition) and inflammation are the growth diversification plays. Gilead generates enormous free cash flow — over $8 billion annually.

Michael Riordan founded Gilead in 1987 in Foster City, California. The company transformed HIV treatment with its single-tablet regimens, starting with Atripla in 2006. Sovaldi's launch in 2013 at $84,000 per course cured hepatitis C but sparked a national debate about drug pricing. The Immunomedics acquisition in 2020 was Gilead's biggest bet on oncology diversification.