Herbalife Ltd. shares posted their biggest ever same-day gain after the company announced talks with the U.S. Federal Trade Commission.

Bloomberg reported Friday that the move that could resolve a longstanding dispute over whether the company operates as a pyramid scheme.

According to a statement released by the Los Angeles supplements company, it is in discussions with the FTC regarding a potential resolution of these matters.

The announcement prompted optimism that Herbalife could overcome the dispute without incurring much further damage. Herbalife shares rose as much as 27 percent to $58.20 in New York after the filing was released, marking the biggest intraday increase since the shares began trading in 2004.

Herbalife, which relies on independent distributors to sell weight-loss shakes, vitamins and other wellness products, disclosed in 2014 that it received a civil investigative demand from the FTC related to the company’s marketing practices.

The government investigation followed allegations from billionaire Bill Ackman, who announced in December 2012 that he was shorting the company and considered it an illegal operation. This led to a three-year battle with Ackman and his hedge fund, Pershing Square Capital Management, which made a $1 billion bet against the nutrition company.

Herbalife also said Thursday that the FTC investigation might still have “a material adverse impact” on its operations or finances. Justin Cole, a spokesman for the FTC, declined to comment about the investigation.