Quote from ak15:
I can short any of these at my firm at an added cost of one and one half pennies per share. The problem is you have to tell them the number of shares you need and after they provide you with the requested amount you will be charged for the amount they provided even if you don't short a single share.
The analogy here is - once you place the order you're stuck with it. No cancellations allowed.
Quote from ChkitOut:
So if you get say 1000 shares, can you short and cover all day or do you need to request every time you open a new short?