Naked shorting: If I short 100 HD at $50 in my Scottrade account, I am borrowing the shares from Scottrade. If Scottrade really doesn't have the HD shares to lend me, it is a naked short. If HD drops to $40 and I cover, I make $1000. Scottrade has to credit me the $1000 in my account, where do they get the $1000 to put in my account?
Cash is King until further notice!!!
My comments on companies are usually my opinion of long term success (years). The PPS may go up or down greatly in the meantime depending on the number of greedy suckers with money.