Herbalife Ltd. (NYSE:HLF) has suffered another downgrade as its stock price continues to fall due to the ongoing Federal Trade Commission probe. “The company posted strong results in 2013, and we believe that its core business remains solid. However, in view of the significant risks posed by the FTC investigation, we think that the shares have limited near-term upside and that a Hold rating is now appropriate,” said a recent note from Argus, reports Tony Owusu at TheStreet. TheStreet is still bullish on Herbalife Ltd. (NYSE:HLF), giving the company a Buy rating on account of its strong revenue, EPS, and…