Shares of Herbalife Ltd., the downtown Los Angeles nutritional supplement company, rose Wednesday after a judge dismissed a lawsuit brought by shareholders alleging they lost money because the business was an illegal pyramid scheme.

In rejecting the suit, which sought class-action certification, the judge found the claimants, including two pension funds, did not show that accusations brought by hedge fund manager William Ackman that the company’s stock price had been artificially inflated had been proved.

Herbalife issued a statement on Wednesday, voicing its satisfaction with the court ruling in the company’s favor.

“Herbalife welcomes the decision by the U.S. District Court for the Central District of California to dismiss the case,” said Julian Cacchioli, a Herbalife spokesman. “As we have consistently stated, we are confident in the strong fundamentals of our business model and remain committed to helping people and communities improve their nutrition.”

Shares of Herbalife closed Wednesday at $38.76, up 13 percent.