Herbalife was up around 6% on day when everybody was expecting David Einhorn
to reveal a short position in the stock at the Ira Sohn Conference. This just doesn't make sense unless someone knew that Einhorn will recommend other stocks and bought Herbalife in anticipation of a huge jump. In fact, Herbalife jumped after Einhorn's presentation and closed the day at nearly $50. It was up 17% today.
I am not sure this counts as ILLEGAL insider trading
though. It is just a positive externality of being close to David Einhorn.