Here is an interesting article from Barron’s about AAPL’s massive 2019 success and the debate on whether or not to sell and harvest gains, then wait for a downturn to buy back in. https://www.barrons.com/articles/apple-stock-diversification-51578691352
I personally will probably just hold onto my shares and buy more during a dip, but considering their one-year growth of 86%, there is a good argument for seeing AAPL shares as expensive.