Billionaire activist investors and longtime rivals Carl Icahn and Bill Ackman are at it again.
This time, the two are tangling over Ackman's short position in Herbalife, a debate that extended itself into barbs over a 10-year-old legal dispute.
In a televised appearance Thursday, Icahn ripped Ackman for publicly revealing a large bet against Herbalife late last year. Icahn reportedly has taken a long position in the company.
In a CNBC interview last month, Ackman labeled the company, which sells weight-loss and nutrition products, a pyramid scheme. He said he had borrowed more than 20 million shares to sell, later hoping to buy them back at a lower price and pocket the difference, a process known as short-selling.
The public nature of the move was "disengenous," Icahn said in a Bloomberg television interview Thursday in which he said he neither liked nor respected Ackman.