Multi-level marketer Nu Skin (NUS) is climbing after Carl Icahn reported last night that he had obtained a 13% stake in Herbalife (HLF), which is also a multi-level marketer. The target of a massive short selling campaign during the last several months by billionaire investor Bill Ackman, Herbalife sells nutritional supplements. Ackman has said that Herbalife is a Ponzi scheme that will ultimately fail. Meanwhile, Icahn stated in an SEC filing yesterday and on CNBC earlier today that Herbalife is undervalued. Icahn also contends Herbalife should examine the possibility of taking the company private. Neither Herbalife nor Nu Skin has been confirmed to be targeted by regulators recently, but the FTC on January 28 sued Kentucky based Fortune Hi-Tech for allegedly operating a pyramid scheme. Fortune Hi-Tech has been placed in receivership. In mid-afternoon trading, Nu Skin rose 1.5% to $42.55, while Herbalife was up 7.5% to $41.14.