What caused the stock market crisis in 2007?

The Stock Market crisis of 2007 was primarily triggered by the collapse of the housing bubble in the United States, which was fueled by risky mortgage lending practices and the proliferation of subprime mortgages. As home prices began to fall, many borrowers defaulted on their loans, leading to significant losses for financial institutions that had invested heavily in mortgage-backed securities. This resulted in a loss of confidence in the financial system, causing stock prices to plummet and ultimately contributing to the broader financial crisis of 2008.