This factbox is part of a special report on a natural gas trading fraud case that can be seen here.

The debut of electronic trading for energy commodities in late 1999 by EnronOnline as U.S. wholesale power markets were deregulated preceded a series of scandals that shook energy and financial markets.

2000-01: California electricity prices soar and the state is hit by rolling blackouts due to poor market rules and schemes created to manipulate prices used by Enron traders and others.

November 2001: Enron restates earnings due to accounting irregularities; liquidity issues rapidly reduce the company's ability to trade power and gas.

December 2001: Enron files the bankruptcy, the largest-ever filing at the time.

March 2002: California sues several wholesale power companies for alleged profiteering during the state's energy crisis. The Federal Energy Regulatory Commission eventually finds "massive" manipulation by a host of players and orders refunds of $1 billion to the state's customers.

April 2002: FERC creates Office of Market Oversight and Investigations to watch power and gas markets.

May 2002:Top executives at Dynegy and CMS Energy Corp resign. These and other firms, El Paso Corp , Reliant Resources, Aquila Inc and Williams Cos cut trading staff and sell assets as they scale back or exit gas trading activity to halt tumbling credit ratings.

August 2002: Trading platform IntercontinentalExchange sees higher volume after demise of EnronOnline; introduces clearing services for over-the-counter power products.

2003-2005: U.S. Commodity Futures Trading Commission levies millions in fines against units of Duke Energy, El Paso Corp, Williams, EnCana Corp, Reliant and CMS for reporting false natural gas trading information.

Aug 2006: MotherRock hedge fund loses about $230 million attributed to wrong-sided natural gas bets.

Sept 2006: Amaranth Advisors LLC hedge fund loses more than $6 billion through bad bets on natural gas futures prices. Energy trader Brian Hunter blamed for the bets, one of the largest known trading losses and hedge fund collapses in history.