If I were to venture a guess, I would say positive Phase 3 Amigal results. I don't have idea what the stock may do on that news. I have no position in the stock and I don't think positive Amigal results are enough to sway me. jq1234, turtle (maybe others?) and I have had discussion about this in the past if you want to search this board (I don't have search but you do ).
While the disease focus is similar to BMRN I wouldn't say they are anywhere near being an up and coming BMRN. If their chaperon would work in Pompe it'd be more interesting to me. Perhaps in Alzheimer's or Parkinsons they'll get lucky but that is a speculation I don't want to pay for at this stage.