In the years leading up to the 2008 financial crisis, a group of ambitious young bankers at J.P. Morgan pioneered a new financial instrument known as the credit default swap. Initially designed to manage risk, these complex derivatives were soon adopted by banks worldwide, fueling a massive, unregulated global credit boom. As the market expanded, banks began packaging subprime mortgages into these instruments, creating a dangerous web of interconnected debt that ultimately led to the most severe economic crisis since the Great Depression.