Every quarter at the CC they will announce how many shares they retired. They plan to do an "accelerated" repurchase program. In other words they pay the banks a set amt per share now, and the banks retire a set number of shares over an agreed period. that locks in the share price for apple. If they chose not to retire any shares the shareholders would of course find out at the CC. Expect at least 10% of the 150 million shares to be repurchased by the end of Q3. The effective float right now is about 300M (640M are in mutual funds) so the effective float should go down to 285M by end of Q3. Also new income funds are likely to gobble up shares as well. We could be looking at only about 100M floating shares by end of 2014.
At their discretion. But watching the short history, and the new buyback artist at Apple, I can tell you they'll do it in a way to cause the most pain to shorts. It will be a long, protracted, pain by cuts of thousand knives. In my opinion this is in response to conjectured $5B Samsung used to short Apple stock. All the other shorts are collateral damage. Note that for this to work correctly, shorts are needed. So it will be pop, base, pop base , down, base all the while encouraging shorts to short. Sit back and enjoy the show.