I'd sell, since you've got great gains and it's not a taxable event. And I'd sell it all, since you describe yourself as an indexer at present. This is an enormous allocation to a single stock. Yes, it's worked out well. But it's still a huge allocation - generally the rule of thumb I follow is is that you can keep up to 10% of your assets in a single stock, if you work there and acquired the position through an ESOP or performance shares, etc. Unless you're a C-level exec or manager at AAPL (who is being incentivized through his/her holdings), there's no reason to have so much of your portfolio in one stock. Pat yourself on the back and take some risk off the table.
Alternately, if that didn't convince you, I have (in the spirit of face-punchyness) also written a ruder version of my advice:
Are you fucking kidding me? You're not a college student day trading shares of of
some penny stock involved in medical marijuana because you think the goddamn ticker's hilarious. OK - granted, Apple's not a penny stock. But this is
a third of your investable assets. You are a
mustachian, relentlessly focused on optimizing your portfolio, and getting the best return you can for a chosen level of risk, at the minimum possible expense.
This is not a businesslike way to manage your portfolio. If you're an indexer, then repent your stock-picking ways, sell the damn stock, and move on with your life. You can tell the story at cocktail parties for the next decade. If you're NOT an indexer, then fine - but you should not be holding individual stocks if you haven't got some fundamental analysis showing why you think the hassle and risk of this position is worth it.
"I like their products and I think the iPhone 6 is gonna be a hit" is not valid fundamental analysis. That's bullshit analysis, and a bullshit reason to continue subjecting yourself to this kind of risk. $30,000 is not only a third of your investments, it's also an objectively large amount of money. For most people on the MMM boards, that is probably nearly a year - maybe more - of living expenses. You're telling me that you'd be zen about if if you knew it was cut in half? COME. ON. Sell the stock, re-invest into your normal asset allocation, and consider it walking out of a casino with some of the house's money.
</rant>
OK, I'm not actually butt-hurt, or shouting at you, Allen. But I toyed with both versions of this response and couldn't pick one.
My actual "do the logical thing" advice would be to sell it all immediately and re-invest into indexes fitting your asset allocation. My "human beings are not logical automatons, they are illogical bags of meat" advice would be to sell $20k immediately and hold $10,000. You'll still feel like you're 'playing the game', but you'll reduce your level of risk to a level that's not insanely high.
Either way - best of luck! Let us know what you pick.