Apple is an icon - a brand name that will stick with present And future generations. No need to sell if it rises or fall in your portfolios. Sell only if u need the cash. Rise or fall it doesn’t matters
Different people will have different strategy in investing or maintaining their portfolio. One strategy you can consider adopting is to create three separate "baskets" of investments - for Long, Medium and Short terms. Your LONG Term basket is kept for more than 5 years and it should be able to weather the market volatility i.e. you should not need this money till >5 years and can afford to take more risks (e.g. 100% equity). Your MEDIUM basket will consist stocks, bonds and REITS (or your standard well diversified portfolio) that has a time horizon of 1 to 5 years. It should be maintained at an amount equivalent to about four times your annual expenses. The final SHORT basket is akin to your current account, kept at roughly about one year of expenditure and placed in Money Market