Carl Icahn: Why I'm Betting on Herbalife

Billionaire investor Carl Icahn, who revealed a 12.98 percent stake in Herbalife in a 13D filing, said Friday that Bill Ackman's $1 billion short interest in the company was "a scheme."

"I buy things I think are undervalued," he said.

Icahn, who publicly battled with Pershing Square Capital's Ackman three weeks ago on CNBC's "Fast Money Halftime Report," was shown to have purchased 14 million shares of the multilevel-marketing nutrition company in his most recent Securities and Exchange Commission filing.

"It's a great company to take private," he said. "I think there's a great deal of money to be made here today."

(Read More: Ackman: Herbalife Short Unaffected by Icahn Stake)

The comment echoes what the chairman of Icahn Enterprises said in his 13D filing, which raised possibility of seeking alternatives for Herbalife, including recapitalization or taking the company private.

Icahn said he was taking the long position to make money, regardless of his personal feelings about Ackman.

"I'm not going to lie to you and say if he gets squeezed, I'm going to cry and do penance," he said.

"The fact that I don't like Ackman you can say is the strawberry on top of the ice cream."

Trader disclosure: On Feb. 15, 2013, the following stocks and commodities mentioned or intended to be mentioned on CNBC's "Fast Money" were owned by the "Fast Money" traders: Jon Najarian is short puts in HLF; Jon Najarian is short puts in CSTR; Jon Najarian is short long call spreads in FRX; Jon Najarian is short long call spreads in LULU; Jon Najarian is short long call spreads in INCYPete Najarian is long AAPL; Pete Najarian is long BAC CALLS; Pete Najarian is long JPM CALLS; Pete Najarian is long MS CALLS; Pete Najarian is long YHOO CALLS; Pete Najarian is long BBRY; Pete Najarian is long BBRY CALLS; Pete Najarian is long SBUX; Pete Najarian is long FB; Pete Najarian is long MSFT; Pete Najarian is long GE; Pete Najarian is long BX; Enis Taner is long GS; Enis Taner is long SPY PUTS; Enis Taner is long C PUT SPREAD; Enis Taner is short QCOM PUTS SPREAD; Enis Taner is long TSLA Call Calendar; Stephen Weiss has nothing to disclose.