Everyone has been badmouthing this stock, but I can find absolutely nothing wrong with it. I hear no reasons for why it should be down except for people saying it was "too high" before. Look at how low their p/e is, look at how well the iPad mini is doing. It seems so undervalued. I'm not complaining, I bought at 575 a few months ago and then sold at 650. I've been buying again, and am confident it will go back up over 700. I'm excited about it, but wonder if I'm missing something because no else seems to like it.
IMO, product shortages and the possible effect on revs is what is holding the price down. (I checked my local AT&T store and was told that they don't know when they will get more iPhones.) Since Apple has not indicated when production will catch up with demand, investors fear the effect on revenues and are reacting to that fear. When the supply issue is resolved, I expect a sharp rebound in the share price.
You are doing the right thing, buying low and selling higher to take your profits. Many people are too greedy to buy and sell with 10%+ profits, they expect the stock to climb straight up to $1000 before they sell!
The stock is moving lower because people are taking profits while tax rates are low (2012). Next year, it is very likely that rates will go up no matter who wins the white house. Since AAPL is very widely held, folks are beginning the selling now...