The Banking Act of 1933 introduced banking reforms designed to control speculation. Some provisions of the Act were repealed by the Depository Institutions Deregulation and Monetary Control Act of 1980. Provisions that prohibit a bank holding company from owning other financial companies were repealed by the Gramm–Leach–Bliley Act of 1999.
The repealed provisions removed the separation between investment banking and commercial banks and removed conflict of interest prohibitions between investment bankers serving as officers of commercial banks. Most economists believe this contributed to the Financial crisis of 2007–2011 by allowing investment banking firms to gamble with their depositors' money that was held in commercial banks owned or created by those same investment firms.