Vertical integration

In the U.S., the Glass-Steagall Act, initially created in the wake of the Stock Market Crash of 1929, prohibited banks from both accepting deposits and underwriting securities which led to segregation of investment banks from commercial banks. Glass-Steagall was effectively repealed for many large financial institutions by the Gramm-Leach-Bliley Act in 1999.

Another development in recent years has been the vertical integration of debt securitization.Previously, investment banks had assisted lenders in raising more lending funds and having the ability to offer longer term fixed interest rates by converting the lenders' outstanding loans into bonds. For example, a mortgage lender would make a house loan, and then use the investment bank to sell bonds to fund the debt, the money from the sale of the bonds can be used to make new loans, while the lender accepts loan payments and passes the payments on to the bondholders. This process is called securitization.

However, lenders have begun to securitize loans themselves, especially in the areas of mortgage loans. Because of this, and because of the fear that this will continue, many investment banks have focused on becoming lenders themselves,  making loans with the goal of securitizing them. In fact, in the areas of commercial mortgages, many investment banks lend at loss leader interest rates[citation needed] in order to make money securitizing the loans, causing them to be a very popular financing option for commercial property investors and developers   Securitized house loans may have exacerbated the subprime mortgage crisis beginning in 2007, by making risky loans less apparent to investors.