I wanted to give a visual of what happens underneath Apple's surface. This data is specific to 02/10/12 weekly opex. The two area graphs represent the highest volume, one for each call and put. The two line graphs represent the actual OI after the close. This is actually what was left on expiry or going into Saturday. You will not find this data elsewhere.
I want to concentrate on the highest volume strikes for the day. This happens to be ~46K contracts on the $490 puts and ~70K contracts on the $495 calls. I do not want to get into delta/gamma hedging, but concentrate on what happens when options close. When a call closes it causes selling pressure. When a put closes it causes buying pressure. In the above graph I want to display a visual. Picture the call 'pyramid' collapsing as calls close down. This sends the stock straight down hill. Now, picture the put 'pyramid' collapsing. This sends the stock higher. Both forces repeal AAPL, squeezing it harder and harder until -- the closing bell rings. You can also think of these like two opposing magnets. AAPL is the ferrous metal forced to the center of these two magnets.
Apple's trading range was $488.55 - $497.62 with a closing price of $493.42. This happened to be right in the middle of the highest put and call volume. While all this is short-term trading info, I hope it helps shed some light if you are ever scratching your head on AAPL's trading patterns.