In the years leading up to the crisis, financial institutions had increasingly engaged in the practice of securitizing mortgages, which involved pooling numerous mortgages into a single financial instrument and selling shares in that instrument to investors. This allowed banks to offload risk and free up more capital to lend, thereby fueling further housing market growth. However, as housing prices began to decline and defaults on subprime mortgages soared, the value of these mortgage-backed securities plummeted, causing massive losses for banks and other financial institutions.
