Old age is no barrier to HCP's profits. The company is a self-administered real estate investment trust (REIT) that invests in, develops, and manages real estate that it leases to health care facilities. Its diversified real estate portfolio consists of hospitals, medical office buildings, and biotech and pharmaceutical laboratories. HCP has interests in properties in 40-plus states and Mexico. California and Texas are its largest markets. The REIT, which has nearly $24 billion in assets under management, invests in properties through direct ownership, mortgage loans, and joint ventures.