Google " Apple share buyback "
This was announced in March 2012, and scheduled to begin in October of 2012. It is a $10 Billion event to be carried out over 3 years. I am surprised how many do not have this info correct. There will be no 'warning' of the buybacks, as the shares are bought directly on the open market. The only confirmation of this will occur at Earnings, as to the scope of the shares repurchased.