This Is Why Shorting Stocks Is So Brutal (PBYI, HLF)

It's just not a great idea to short stocks. Last night, drug development company Puma Biotechnology reported better than expected breast cancer trial results, and shares of the company rallied nearly 300% afterwards. Yesterday, activist investor Bill Ackman gave the "most important presentation of his career," regarding his short position on Herbalife. During Ackman's presentation, Herbalife shares rallied. If you were long shares of Puma Biotechnology before last night's close, your position is...