my take is that the surge through 40.50 suggests that there is some chatter of another offer. One hypothesis is that counter offers come into play and go public solely to force amazon to pay more thus taking on more risk. I speculate competitors are thinking counter offers on the grounds of attempting to keep amazon out of the play (which won't work). Amazon hasn't been stopped yet. apparently WFM agreed to a non-shop clause with amazon...receiving other offers and deals comes at a 400 million penalty