Passage: The Financial Crisis Inquiry Commission reported in January 2011 that: "From 1978 to 2007, the amount of debt held by the financial sector soared from $3 trillion to $36 trillion, more than doubling as a share of gross domestic product. The very nature of many Wall Street firms changed – from relatively staid private partnerships to publicly traded corporations taking greater and more diverse kinds of risks. By 2005, the 10 largest U.S. commercial banks held 55% of the industry's assets, more than double the level held in 1990. On the eve of the crisis in 2006, financial sector profits constituted 27% of all corporate profits in the United States, up from 15% in 1980."Many financial institutions, investment banks in particular, issued large amounts of debt during 2004–07, and invested the proceeds in mortgage-backed securities (MBS), essentially betting that house prices would continue to rise, and that households would continue to make their mortgage payments. Borrowing at a lower interest rate and investing the proceeds at a higher interest rate is a form of financial leverage. This is analogous to an individual taking out a second mortgage on his residence to invest in the stock market. This strategy proved profitable during the housing boom, but resulted in large losses when house prices began to decline and mortgages began to default. Beginning in 2007, financial institutions and individual investors holding MBS also suffered significant losses from mortgage payment defaults and the resulting decline in the value of MBS.A 2004 U.S. Securities and Exchange Commission (SEC) decision related to the net capital rule allowed US investment banks to issue substantially more debt, which was then used to purchase MBS. Over 2004–07, the top five US investment banks each significantly increased their financial leverage (see diagram), which increased their vulnerability to the declining value of MBSs. These five institutions reported over $4.1 trillion in debt for fiscal year 2007, about 30% of US nominal GDP for...

Question: What area dealing with money was made more unstable due to these failures?
the global financial system