Likewise one of my highest conviction holdings. (My basis does happen to be over the $300 mark; not concerned.)
It is on top of my targets to add, in the near future.
Besides all your normal financial research, there are some very useful anecdotal to the point comments regarding ABMD’s ‘product’, see postings from “HeartMD”, there are only a few board postings from a very busy cardio; quick reads, and more useful than most analysts’ insight. Worth bookmarking.
https://discussion.fool.com/sauls-investing-discussions-120980.a…
(Lots of other non-ABMD posts in the list; concentrate on the obvious ABMD subjects.)