Halo is a minor position for me. It's a technology that allows for a switch from infused drugs to injectable. Roche has partnered with them for 4 antibody switches with options for 10 more. The 4 are all early in the clinic but could move rapidly if Roche is motivated. Baxter is working on switching an infused plasma drug ($1b+) to injectable and that's in phase 3 in a very low risk filing strategy.
Why its not a big position for me is i'm not as sold on halo's internal ideas such as rapid acting insulin which they seem to be placing their biggest bet.