”

Pickens, 89, also cited his health in the post, writing, “I’m still recovering from a series of strokes I suffered late last year, and a major fall over the summer.” He added, “It’s time to start making new plans and setting new priorities.”

Though he achieved much of his fame for corporate takeover bids in the 1970s and 1980s, Pickens earned much of his wealth in the energy futures buy Wellhead market after turning 75 in 2003, making billions through his Dallas-based BP Capital LLC by correctly betting on rising prices for oil and natural gas.

Hard Decade

Pickens was managing more than $4 billion at the start of 2008 before one of his funds was almost completely wiped out and a second plunged 64 percent. Undaunted, he sought out new investors the next year for new hedge funds that invested in stocks and futures. As of mid 2016, the equity holdings had a value of $218 million.

Pickens probably fell victim to diminished volatility in energy markets, according to Rob Thummel, who helps manage $16 billion in energy assets at Tortoise Capital Advisors LLC. “It’s a sign that oil volatility is probably not coming back for a while, and that’s what traders are looking for,” Thummel said by phone. “It’s not as lucrative.”

In the latest Forbes Magazine listing, Pickens’s net worth is listed at $950 million in 2013, reflecting losses from the 2008 financial crisis, hundreds of millions Pickens spent on philanthropy (including about $500 million to Oklahoma State University, his alma mater) and investments in wind energy, part of his plan to end U.S. dependence on Middle East oil.

Not all of his energy investments will be shuttered, according to the posting. Pickens said he will continue to be an owner and investor in the TriLine Index Solutions energy index series and the BP Capital TwinLine Energy Fund.

In December, Pickens put his 65,000 acre (26,305 hectares) Mesa Vista Ranch in the Texas Panhandle up for sale, with an asking price of $250 million, according to the Dallas Morning News.

Pickens was probably known best as a corporate raider in the 1980s before he became a billionaire energy investor and television pitchman for wind and natural gas.

“There’s no one, probably other than Warren Buffett, who’s seen and actually lived through all these cycles in oil,” Thummel said.

To contact the reporters on this story: Laurence Arnold in Washington at This email address is being protected from spambots. You need JavaScript enabled to view it.; Meenal Vamburkar in New York at This email address is being protected from spambots. You need JavaScript enabled to view it.. To contact the editors responsible for this story: Reg Gale at This email address is being protected from spambots. You need JavaScript enabled to view it. Joe Carroll, Debarati Roy.