An act passed by Congress in 1933 that prohibited commercial banks from collaborating with full-service brokerage firms or participating in investment banking activities.

|||The Glass-Steagall Act was enacted during the Great Depression. It protected bank depositors from the additional risks associated with security transactions. The act was dismantled in 1999. Consequently, the distinction between commercial banks and brokerage firms has blurred; many banks own brokerage firms and provide investment services.