"I have some AAPL shares and want to keep a core holding; 1) where should I put my trailing stop, and  2)what percentage of AAPL that I have should be that core holding. I bought  AAPL @ 210.99 Thoughts from anyone are welcome.  Thank you." Winter 39

Winter 39: Since it's a slow day here are a few answers on portfolio management from a few books I have re-read lately.: Nicholas Darva "How I made 2 million in 18 months..." invested everything in 2 stocks and then putting everything into just one, that he was absolutely sure of, raising his stop along the way. Jessee Livermore" Reminiscences of a stock operator" did the same, plunging big, never using stops, or using charts..and going all-in in one or two positions,  making and losing several fortunes along the way. (eventually shooting himself). I myself, after losing 15% of my portfolio trading ES with no stops, now never risk more than 3% of it in any one position or 5% in any one industry and only use options to know my risk ahead of time. Portfolio management rules are many and varied. Which ones fit you is your choice. (I'm sure many others here can offer other ideas- hope that helps.