Billionaire hedge fund manager Carl Icahn told CNBC on March 1 that he'd made $1 billion in paper profits from his long position in Herbalife Ltd. (HLF), the controversial multilevel marketing company at the center of a five-year battle between Icahn and another billionaire (by a hair) hedge fund manager, Pershing Square's Bill Ackman.

That battle came to an end on Feb. 28, when Ackman told CNBC that he'd unwound his short position in Herbalife. The stock popped on the news, ending the day up 6.3% at a record close of $92.10. "I enjoy a good fight, especially when I win it," Icahn told CNBC the following day.

Ackman announced his bet against Herbalife in dramatic fashion on Dec. 20, 2012, telling the Sohn Conference in New York City that he had a $0 price target on the "pyramid scheme" and presenting 342 slides' worth of evidence for his opinion. The stock had closed at $37.34 the previous day, meaning it has since risen 147% in the intervening time. 

Within a month of Ackman's presentation, Icahn rumored to have taken a long position in the company. Tensions came to a head in a heated argument live on CNBC. During the course of half an hour, the two raked over disputes going back a decade. Ackman described Icahn as a "bully" who "takes advantage of little people" and "does not have a good reputation for being a handshake guy"; Icahn called Ackman "the crybaby in the schoolyard" and a "liar," adding, "[I] rue the day I ever met the guy."

Five years later, following the annoucement that Ackman had exited his position, Icahn said, "I honestly in a strange way I thank Bill," adding, "I wish him well." Icahn says Ackman called to congratulate him. (See also, Bill Ackman Dumps Herbalife.)

A Moral Crusade

Ackman and Icahn's tug-of-war over Herbalife did not just make great TV: it provided material for a critically acclaimed film, Betting on Zero, released in mid-2016. The film followed Ackman's line, portraying Herbalife as a pyramid scheme that exploits ambitious but ill-informed entrepreneurs, many of them low-income immigrants, most of whom lose their own money and that of family and friends – ending up with only boxes of unsellable dietary supplements.

It was later revealed that a third hedge fund manager, John Fichthorn, financed the film; Fichthorn's fund had held a short position in the company until early 2014. (See also, What Is a Pyramid Scheme?)

In July 2016, the Federal Trade Commission closed a probe into the company, accepting a $200 settlement from Herbalife and an agreement that the company would change the way it compensated its distributors. The company's board cleared Icahn to take a stake of up to 35%. As of October 2017 his stake exceeded 26%.

"I think Herbalife is a great company, makes great products," Icahn told CNBC on March 1.