This is interesting
The institutional holdings report just became public from 9/30/19.
Most of the institutions with large holdings increased shares of IMGN with the exception of Clearbridge which sold a few shares. In particular Renaissance Technologies, arguably the #1 Hedge fund, increased their position 1.6 million shares owning about 5.7% of IMGN stock. Hedge funds double down on promising companies that are perceived to have a depressed stock price. The bad news is that they can get out quickly with high frequency trading which can make the price more volatile. Overall institutional ownership has increased to about 73%.
I view this report as a positive vote of confidence.