With a market cap of $214.7 billion, Citigroup Inc. (C) is a global financial services holding company that provides a wide range of banking, investment, and wealth management solutions to consumers, corporations, governments, and institutions worldwide. The company operates through five business segments: Services; Markets; Banking; U.S. Personal Banking; and Wealth, offering products such as treasury solutions, securities services, investment banking, lending, and retail banking.
Companies worth more than $200 billion are generally considered "mega-cap" stocks, and Citigroup fits this criterion perfectly. It serves clients across North America, Europe, Asia, the Middle East, Africa, Australia, and Latin America through its extensive international network.