They trip as many stop losses as possible - there is a big gap that could fill IMO but lovethatgreen has pointed out that arna has other gaps that haven't filled. So I'm guessing 4.50 - 5 is bottom and the back up from there and then it's a roller coaster till FDA meeting . But that's only my 2 cents
Many will bail out to wait for a lower SP to get back in. Many will wait for the PO share numbers to see how many shares will be hitting the common shares structure.