Kenneth Lay, Enron
In some ways, Kenneth Lay was Enron. Lay helped create the company in 1985; by 2000, he had turned it from a simple natural-gas corporation into an energy-trading giant worth $68 billion. But much of that money was based on shady accounting practices and losses not recorded in its financial statements. Investment analysts began to question the company's viability in March 2001. By October of that year, the U.S. Securities and Exchange Commission had opened an investigation into Enron's accounting books. Within one year, the company's stock price plummeted from more than $90 to less than $1, causing shareholders to lose $11 billion. Enron subsequently filed for Chapter 11 bankruptcy; at the time, it was the largest corporate bankruptcy in the U.S. Lay and fellow Enron exec Jeffrey Skilling were convicted in 2006 of fraud and conspiracy. Skilling is currently in jail; Lay died from a heart attack while awaiting sentencing.