I agree, chart-wise it looks perfect, similar to the setup for CHP late last week.
The difference with ARNA is that this whole drop is news driven, so a subsequent reversal may need to be news driven as well.
Though, I think the chart setup is partially due to shorting, so when those folks cover (my guess is soon) then I think we get a decent bounce. I'm looking for more than $2 though, I think it's got at least $2.20 on the short cover alone, and potentially $3 if the news is right. If both hit, it may fill that gap to $3.50, but I'll be long gone by then...
