ACAD is a really unique opportunity and their involvement is wonderful. I think they additional buying that they're doing should give confidence. However, I wouldn't follow any group blindly as some of those stocks may be good and some bad. They bet on lots of things...but when they double and triple up (like they've done here) it's wise to listen. They take lots of small positions and will build if the story gets good. And they miss some too....they sold off their YMI position 6 months or so before Gilead bought them.
My point...Acadia is an awesome company with or without Baker Bros. I would be buying even if they weren't here....however, I'm happy that they are here!