Enron scandal — Trading and mark-to-market · 139

Investigations by the U.S. Department of Justice, the SEC, and a special committee of Enron's own board (the Powers Report, February 2002) described mark-to-market accounting used on thin evidence, special-purpose entities that hid losses, and an auditor, Arthur Andersen LLP, that was destroyed by the obstruction case that followed, even after the Supreme Court later reversed Andersen's conviction in 2005.

Jeffrey K. Skilling was convicted in 2006 in the Southern District of Texas. Kenneth L. Lay was also convicted that year but died before sentencing, and the court vacated his conviction. Andrew S. Fastow, the former CFO, pleaded guilty in 2004. Congress answered with the Sarbanes-Oxley Act, signed 30 July 2002, the statute most often cited as Enron's legal monument.

The Powers Report, the criminal dockets in Houston, and the Andersen case are the primary public sources. They describe accounting choices and off-balance-sheet structures that courts later treated as fraud, not a single missing ledger. Enron expanded from a pipeline company into a trader of energy and other contracts. It used mark-to-market accounting, permitted in some contexts, to recognize estimated values of long-term deals as current earnings.