IMUGENE CHART. TA only, page-27613

The way I understand it is that the 8% isn't the issue as they have already sold and taken their short position hoping for a lower price to buy and close their short position. This may effect sentiment though. The problem is funds and instos with very large holdings that have the power to sell down massive amounts, trigger stops, lend more out for further shorting etc. Perhaps they work together with shorters by creating negative sentiment, big sell down, create panic, trigger stops, then buy back up to accumulate. Very lucrative if we're talking about the kind of volume they play with.
But that is just my limited understanding, may be wrong. I wouldn't even know how to go about opening a short