It is not possible to short a penny stock. I called ALL the mainline brokerage houses: Etrade, Scottrade, T.D. Ameritrade, Schwab, Interactive brokers. They ALL told me that they could not margin shares of a penny stock for shorting. NOT ONE OF THEM CAN DO IT!!! I am sick of people attributing a certain price action to shorting. The only entity that can short a penny stock is the market maker himself, and he would be putting his license on the line by doing it. Go ahead and call them yourself! YOU CAN'T SHORT A PENNY STOCK!