WorldCom

WorldCom's 2002 bankruptcy was the largest in US history at the time, fueled by $11 billion in accounting fraud that disguised operating expenses as capital expenditures. Once America's second-largest long-distance phone company with $35 billion in revenue, its collapse destroyed $180 billion in shareholder value—more than double Enron's $74 billion loss. CEO Bernie Ebbers was sentenced to 25 years in prison, and the scandal directly led to the Sarbanes-Oxley Act of 2002. While Enron's fraud was more intricate, WorldCom's deception cost shareholders over twice as much, making it an even costlier cautionary tale.