John Arnold, a former Enron trader and hedge fund honcho known as the “king of natural gas,” is backing an energy-focused credit fund that will aim to take advantage of commodity prices at multi-year highs, sources familiar with the matter said.

Arnold, who reportedly made around $750 million trading natural gas for Enron in the same year it went bankrupt, is backing Energy Opportunities Capital (EOC) Partners LLC through his family office.

Centaurus Capital LP has committed around $500 million in equity for EOC Partners, according to the sources.

EOC Partners is run by two former managing directors of energy private-equity firm EIG—Richard Punches, who headed oil and gas investing at the firm, and Nick Fersen, who worked on credit investments—according to a March 30 filing with the U.S. Securities and Exchange Commission.

While EOC’s filing did not specify a target industry or investment size, the sources said it was exploring debt financing deals of between $50 million and $200 million in the oil and gas exploration and production industry.

The sources requested anonymity to discuss confidential matters. Arnold and his family office did not respond to emails requesting comment. Punches declined to comment.

EIG did not immediately respond to a request for comment.

Arnold rose to become head trader at Enron but after its collapse, which was one of the worst financial scandals in U.S. history, he launched Centaurus Advisors. His bets on natural gas prices at the hedge fund made him the youngest U.S. billionaire in 2007.

In 2012, however, with natural gas prices plummeting, a 38-year-old Arnold retired from managing others’ money to focus on philanthropy with his wife. Through his family office though, he has continued to invest in the energy industry.

The backing of EOC Partners coincides with natural gas trading at levels not seen since the era when Arnold made his fortune, as Russia's invasion of Ukraine crunches global supply just as demand is returning to pre-pandemic levels.

U.S. natural gas futures traded at $8.26 per MMBtu on May 17, more than double their price at the start of the year. Earlier this month, they soared to $9, their highest level since 2008.