Again, the thinking on AAPL should be, there's no reason to sell this thing until we have proof the company has beat itself (because the "competition" isn't doing it) and damage lurks imminently. That's not happening for quite some time. However, just as investors must see the obvious vis-a-vis Apple's dominance, they need to bring a clear mind to the assessment of individual stock ownership. In a perfect world, you should be able to buy and hold AAPL. And, despite the wild gyrations, you pretty much have been able to. Sure, if you held steady in 2012, you left some money on the table from September through the end of the year, but you still recorded considerable gains. And now, early in 2013, you're making up what you "lost" on paper. AAPL shouldn't go up in a straight line. No stock does. No stock should. But it also should not be as volatile as it is. But, it is. So what do you do? That's a personal decision based on your financial situation and risk aversion. But, one thing's for sure, it might not make sense to be a pure buy-and-hold investor, even with AAPL. Keep a core position maybe, but trade in and out of a significant chunk. I'm not talking nimble day or even swing trading. I'm talking, "hey look, that lot is up 35%, let's not press our luck because even though the other guy is an idiot, he can still make money in this market." Follow @rocco_thestreet --Written by Rocco Pendola in Santa Monica, Calif.