An investment bank is a financial institution that assists individuals, corporations, and governments in raising financial capital by underwriting or acting as the client's agent in the issuance of securities. An investment bank may also assist companies involved in mergers and acquisitions (M&A) and provide ancillary services such as market making, trading of derivatives and equity securities, and FICC services (fixed income instruments, currencies, and commodities).
Unlike commercial banks and retail banks, investment banks do not take deposits. From the passage of Glass–Steagall Act in 1933 until its repeal in 1999 by the Gramm–Leach–Bliley Act, the United States maintained a separation between investment banking and commercial banks. Other industrialized countries, including G7 countries, have historically not maintained such a separation. As part of the Dodd–Frank Wall Street Reform and Consumer Protection Act of 2010 (Dodd-Frank Act of 2010), the Volcker Rule asserts full institutional separation of investment banking services from commercial banking.