A branch of banking that coordinates massive, intricate financial transactions like mergers or the underwriting of initial public offerings (IPOs). In addition to underwriting the issuing of new securities for a corporation, municipality, or other entity, these banks may raise money for businesses in a number of other ways. They could oversee an organization's initial public offering (IPO). They will offer guidance on reorganizations, mergers, and acquisitions. Investment bankers are professionals who are acutely aware of the state of the markets and investment climates, and assist their customers in navigating the challenging world of high finance.