Unfortunately, a common trend has been established in the last few months that consists of a News Pump, to make a quick 10-20%, then an immediate Profit Dump, and a Short to double gains. As such, most of the action lately has been P&D.
With that said, some of the buying as been by large long term holders trying to cash in on the potential future of the company, myself included. Im not worried about what happens to the PPS at the moment. As fare as im concerned, anything that drives the price down gives people like myself the opportunity to buy more shares at a lower price.
Until the company has a solid revenue generating product, these clinical discoveries will likely not be enough to hold the share price up. As with most stocks, the short term price will be determined by the battle between the short and long term investors.
I say let them short it, let them dump it... ill take their shares, i see a lot of potential with this one :)