Golf, 9,000 shares traded in 4 hours, and the super-low volume the past several weeks is simply lack of interest right now. I suspect most institutional investors are waiting for the outcome of the trial(s), as the outcome is going to swing the stock price one way or the other. Not that a negative outcome is a death knell, but the stock price will swing down temporarily if it does. Creating (yet another) buying opportunity.
Here's the other thing...a lot of institutional investors look for quick "wins". A temporarily mispriced stock, one with upcoming events, or something similar. Sarissa and management have been so mum about any of their plans, that it gives the appearance that nothing is happening anytime soon. So my guess is that they are waiting for when they believe a strong move is more imminent, rather than "parking" cash with AMRN right now.
It will be interesting to see if volume accelerates around the SC case.