knife catcher, page-12

My Guess....The short seller has either borrowed the stock(not in this case) or entered into a borrowing arrangement(naked short as he has not actually borrowed/taken possession of the shares yet in this case,just made the arrangement) which enables the seller to deliver the stock sold at settlement hence, the shorts are starting to cover their naked shorts which in turn means they need the shares from the 'borrowing arrangement'(naked short), making the lending increase so they can cover(reason for PPS rise last 2 days) while shorts sales are actually declining. Not a total pro on this but best reason I can come up with for the chart you supplied. More then happy to hear anyone else's theory.