Long term (5yrs) this is a screaming buy. Short term you might have some anxiety.
5 years is a long time. Anything can happen. If one can look forward 5 years and see "screaming buy" profits in a "what if", one should be able to also look backwards 5 years and see AAPL under $100/share. The past is hard reality. The future is speculation.
This could indeed be a "screaming buy" or it could be a "screaming sell" or anything in between. I've seen similar posts from guys in the slide all the way down from north of $700/share. That's how it always is. Sometimes they guess a bottom right, often they guess wrong. Was it a screaming buy at $650? $600? $550? $500? That didn't work so well. But it will be different this time?
If someone believes this is a screaming buy right now, consider buying cheap call options rather than stock. If you are right, you make almost as much as owning the stock with much less money at risk. If you are wrong, you can only lose the money you spend on the call options at most.
If I had lots of AAPL stock with paper profits right now but I couldn't bear to sell now, I would put in a trailing stop below the point where I just can't imagine it falling (further). Then, if that stop gets executed, I'm out with only the additional loss between here and there. If AAPL does rise from here, the trailing stop will rise along with it, ready to automatically take me out at a higher level should AAPL take another surprise plunge in the future. For any high-flying stock, put on a trailing stop to automate your downside exit. Failing to take profits off the table costs investors an awful lot of profit every year.
The big mistake is having no downside protection beyond just hope. Hope never makes a falling stock go back up, only buyers can do that. Waiting ("I'm giving it another year") never makes a falling stock go back up either; only buyers make stocks go up. If you own a home, do you have insurance should that home burn down? If you own a car, do you have insurance should that car be totaled? If you own a bunch of AAPL, do you have insurance against a sudden loss of value? If the answer is not yes to all of these, you are doing it wrong.