I just want to suggest an option when placing a standard sell order... you still enter your price and quantity as usual but you could have an optional check box that says don't sell below exchange rate (median feed). So the price you enter then becomes the minimum BTSX you will accept for your bitUSD but you will get matched at the feed price ahead of all shorts and compete with them directly. Priority should be first in first out. This is more convenient than losing the spread by selling into whatever bid wall exists or having to carefully place your order just below feed price, only downside is you may have to wait a little for a buyer, but you will eventually move to the front of the line as other sell orders are matched and before any shorts execute.