Without any plans for getting paid by NHS right away ( no evidence submitted yet ) and no idea of ever applying to FDA , not sure how will they get the SP to $4-5 level and also get on a real exchange . Without that happening there is no way Merck will be able to pay $10 per share or more . No buyout of $10B or more has ever paid more than approx 100% premium over pre buy out SP ever . It is usually 10-50% premium in that buy out price range ($10B or more)