<< with such a high percentage of stock held by institutions - who keeps acquiring at these levels? >>
Smart money is acquiring at these levels. Some institutions will take their profit and run with longer-term shareholders buying up their shares. I think the heavy selling of short term owners is about done and we could see some significant appreciation in the near-term.
We should see more sell-side analyst upgrades announced throughout this week with increased price target's in the mid-to-upper 30's.
Also, there are plenty of institutions that never heard of MNTA until Friday. After some DD I'm sure a good number of them will realize MNTA has an exceptional risk-return profile and will start bidding up the shares.