Pickens began targeting Gulf, the fifth-largest U.S. oil company, in 1983, when its share price was $38. Pickens’s partnership, Gulf Investors Group, worked with Greenberg at Bear Stearns to accumulate shares. Pickens met in New York City with 200 financial analysts and money managers to assure them he was serious about a takeover and wouldn’t strike a separate deal with Gulf.

“It was pouring rain outside,” Slater wrote of the meeting, “but the crowd couldn’t stay away and miss the unusual chance to see what this man was like -- this man with the strange name, with the great derring-do, this man who had sent chills running down the backs of the Wall Street community.”

In the friendly takeover that Gulf eventually agreed to, Standard Oil paid $80 a share. Pickens and his partners had paid an average of $43 per share in building their 9 percent stake.

Pickens took home another consolation prize in 1984, when Phillips -- his onetime employer -- fended off his takeover bid by buying back his stock, giving him a profit of $89 million.

Financing Acquisitions
In changing Mesa to a master limited partnership in 1985, Pickens put an emphasis on returning capital to stockholders, committing the firm to annual cash distributions of $1.50 to $2 a unit through 1990. The structure let him issue new Mesa units to finance acquisitions, such as the 1986 purchase of natural-gas company Pioneer Corp. When the price of gas dropped, those guaranteed distributions became “a killer,” Pickens later said.

Pickens found himself on the target end of a hostile takeover attempt led by former Mesa President David Batchelder. (Batchelder, co-founder of Relational Investors LLC, told the San Diego Union-Tribune that he left Mesa in 1988 because Pickens “started taking himself too seriously and lost his ability to have fun.”) After Mesa’s share price fell below $3, Pickens turned to Rainwater as a white-knight investor. Pickens was forced out of the company he had run for 40 years.

With five former Mesa employees, Pickens opened BP Capital in 1996 to trade energy futures. His BP Capital Energy Fund began trading stocks and futures in 2001, with $84 million from investors.

Winning Bets
Betting correctly on rising crude oil prices, he tripled the money in that fund in the first nine months of 2004. In 2005, the fund made $1.3 billion -- a 248 percent profit, after fees -- on oil futures and natural-gas trades.

“You’ve got plenty of oil, but light sweet is in short supply,” he said in a September 2004 interview, explaining why he believed there would continue to be unmet demand. “The Chinese want light sweet. We want light sweet.”

At the time of that interview, crude oil futures had topped $49 a barrel, the highest in the 21-year history of the contract. By July 2008, when the price peaked at about $147 a barrel, Pickens was a billionaire. Then prices plunged in the second half of 2008, a turn that cost his fund more than $1 billion in losses.