Shares of Los Angeles-based multi-level-marketing firm Herbalife Ltd. (HLF) plunged 9.6% Friday following news that controversial hedge fund manager Carl Icahn had significantly reduced his stake in the company.

Closing at $48.70, HLF reflects a 43.8% return year-to-date (YTD) and a 36.4% increase over 12 months, sharply outperforming the S&P 500's 1.8% gain and 12.7% growth over the same respective periods. 

Investors have applauded the nutritional supplement and weight-loss products company for what has been largely seen as the end of a successful battle against billionaire hedge fund manager William Ackman and his Pershing Square Capital. In 2012, the high-profile investor bet $1 billion against the company as he championed a public campaign to expose it as an illegal pyramid scheme. The fight became personal between Ackman and Icahn, a former "special advisor" to President Donald Trump and one of Herbalife's biggest investors since the end of 2012. Earlier this year, Ackman told CNBC that he had finally thrown in the towel on his short bet. (See also: Herbalife Had 'Secret Dossier' on Bill Ackman.)

A Half-Decade-Long Short-Selling Campaign

On Friday, Icahn's activist hedge fund, Icahn Enterprises (IEP), said in a securities filing that it was tendering up to 11.4 million of HLF shares, marking an approximate 25% divestiture of the 45.7 million shares it currently owns. Icahn will remain Herbalife's largest shareholder. Out of the 29 long-quiet positions Icahn Enterprises currently holds, only three have been held longer than Herbalife, according to the filing. 

"For almost six years, we have been one of Herbalife's strongest, most loyal supporters. We stood by the Company through a half-decade[-]long short-selling campaign; and we never sold a share, even after our investment doubled," wrote Icahn in a statement. "But, given that our Herbalife investment has become an outsized position, representing approximately 24% exposure to total NAV, it is only prudent for IEP to reduce its exposure." (See also: Buy Herbalife Now That Ackman’s Out: Citi Research.)