You will come to the conclusion after you have traded a few...

You will come to the conclusion after you have traded a few years and have gone through ups and downs, hopefully more ups that the market likes certain shares at certain times, and that sector may have a run.

When you get out is when you get out hopefully higher than you bought in, harder to do for young players as the emotional tendency hits, look at the share price, if it is too high waged against your principle then paper trade it and carry the disappointment if it fly's as experience.

Always look around the market as a whole, it will become a full time job.

I started in 98 and time has flown, but i'm having fun. It's nothing of course that you don't really know.

But you asked, and experience sometimes cannot be taught, but remember the market can be a brutal teacher my friend.

take care.