Among the last Wall Street investment banks to jump into the subprime mortgage businesss, Goldman Sachs made a safe exit before a flood of mortgage loan defaults staggered the U.S. and global economies. While Goldman sold over $40 billion in securities backed by risky mortgages in 2006 and 2007, it made secret bets that a sharp drop in the housing market would send those securities plummeting in value. (Lisa Kaplan Gordon/MCT) Lisa Kaplan Gordon / MCT