Investment banking has changed over the years, beginning as a partnership firm focused on underwriting security issuance, i.e. initial public offerings (IPOs) and secondary market offerings, brokerage, and mergers and acquisitions, and evolving into a “full-service” range including securities research, proprietary trading, and investment management. In the 21st century, the SEC filings of the major independent investment banks such as Goldman Sachs and Morgan Stanley reflect three product segments: (1) investment banking (mergers and acquisitions, advisory services and securities underwriting), (2) asset management (sponsored investment funds), and (3) trading and principal investments (broker-dealer activities, including proprietary trading (“dealer” transactions) and brokerage trading (“broker” transactions)).
In the United States, commercial banking and investment banking were separated by the Glass–Steagall Act, which was repealed in 1999. The repeal led to more “universal banks” offering an even greater range of services. Many large commercial banks have therefore developed investment banking divisions through acquisitions and hiring.
The traditional service of underwriting security issues has declined as a percentage of revenue. As far back as 1960, 70% of Merrill Lynch’s revenue was derived from transaction commissions while “traditional investment banking” services accounted for 5%. However, Merrill Lynch was a relatively “retail-focused” firm with a large brokerage network.