Investment Bank Also known as underwriters, investment banks serve as middlemen between corporations issuing new securities and the buying public. Normally one or more investment banks buy the new issue of securities from the issuing company for a negotiated price. The company walks away with this new supply of capital, while the investment banks form a syndicate and resell the issue to their customer base and the investing public. Investment banks perform a variety of other financial services, such as merger and acquisition advice and market analysis.