Which U.S. housing-related securities market helped trigger the Global Financial Crisis crash of 2008?

The subprime mortgage market helped trigger the Global Financial Crisis crash of 2008.

Subprime mortgages were loans made to borrowers with weaker credit histories or higher repayment risks. During the U.S. housing boom, these loans were frequently bundled into mortgage-backed securities and other structured products sold to investors.

When U.S. house prices declined and borrowers began defaulting, the value of many mortgage-linked assets became difficult to assess. Losses spread through banks, insurers, investment funds, and credit markets. The resulting shortage of trust and lending helped turn a housing problem into a global financial crisis.

The subprime market was important, but it was not the entire cause. Excessive leverage, weak underwriting, complex securitization, and inadequate risk controls also played major roles.