one theory...perhaps bnk is part of some oil & gas etfs and, perhaps, these are being shorted with oil down 7%+ last week?
also, there's no guarantee of the take over yet. amaya was also offered to be taken out and looked what happened. not the same situation, i realize that, but the point is you never know what can come out of left field.
i'll be waiting and if it drops 10-15% i'll consider stepping in.