Er, Apple is OBLIGATED to buy back the stock at the lowest price they can. That price shifts. If the person in charge of the TACTICS of the buyback program notices a pointed downtrend he'll exploit it at ANY level . . . Sure, their plan may have a base level where NOT to trade. but I'm betting that high cutoff doesn't have a THING with there being any LOW cutoff wherein they spend what they have to sustain it. In fact he's probably constrained to buying no more than a certain amount of stock per day.
u must be a newbie. what kind of fire do u think cook&co will get for buying back 20bn at $520 if the stock goes below that? they will do what it takes, buyback more, pre-announce earnings, unveil new products, etc. on the other hand u have no thesis for the stock going lower other than your punk airhead blabbing