An investment banker is an individual who works for a financial institution and is primarily concerned with raising capital for corporations, governments, or other entities. They facilitate large, complicated financial transactions, which may include structuring an acquisition, merger, or sale for their clients. Investment bankers are financial advisors to corporations and, in some cases, to governments, and they help their clients raise money by issuing stock, floating a bond, negotiating the acquisition of a rival company, or arranging the sale of the company itself. Investment bankers collect data, make financial models, and advise their clients and employers based on their findings. They work for many types of investment banking companies, ranging from bulge bracket global banks to boutique investment banks. Investment bankers must have excellent number-crunching abilities, strong verbal and written communication skills, and the capacity to work long and grueling hours.