Enron was an energy company that grew rapidly in the 1990s but collapsed in 2001 due to widespread corporate fraud. Top executives, including CEO Ken Lay and CFO Andrew Fastow, had set up off-balance sheet partnerships and used mark-to-market accounting to hide billions in debts and inflate profits. When Enron's fraudulent activities came to light after an accounting scandal, the company filed for bankruptcy in 2001, resulting in losses of over $60 billion for shareholders.