Although buying AAPL low paid off in the short term (AAPL closed Tuesday at US$113.71, up 8.45 points), that strategy isn't necessarily paying off today. Apple is trading at around US$108-109, off about US$5 from the Tuesday close. Still better than US$105, but not by much.
While you shouldn't be day trading unless you know what you're doing, it's important to keep an eye on the portfolio in light of the major swings in the financial markets.
(Note: I don't hold any AAPL stock as stated in my disclosures.)