imo it's simply because investors were expecting FDA green light in July, then Sept, then Oct, and now mgmt is stating q1 of 13'. Bio traders are impatoent and move to whatever is about to run. The bottom is probably real close now and after bounces along the bottom for a time, it will start a steady rise again. After VRNG does it's thing for me, I'll double up on NVIV. It's a screaming buy imo right now.