SL Green Realty Corp., Manhattan's largest office landlord, is a fully integrated real estate investment trust, or REIT, that is focused primarily on acquiring, managing and maximizing value of Manhattan commercial properties. As of December 31, 2020, SL Green held interests in 88 buildings totaling 38.2 million square feet. This included ownership interests in 28.6 million square feet of Manhattan buildings and 8.7 million square feet securing debt and preferred equity investments.