Having greed is good, its the stupid mistakes that make you lose money. Greed is wanting more money, holding more than you should is not "greed", its a mistake, if you know what you are doing then you would sell at the top and buy at the bottom and make more money aka be greedy.
So all in all, do not make all the mistakes confused with each other, because emotions in trading world is very dangerous and mistaking which emotion is which could be even worse and that's an important thing.
Greed is never been good because this would be pushing you on becoming that desperate when it comes to making money which you would really be that not minding about those basic analysis that you have done
earlier just because you had made yourself that confident that you could still make some money.This is why you should really not make yourself that greedy because it would really make some mistakes
that you might be able to regret later on.This is why proper handling of emotions and and self control is really that necessary specially when dealing up with trading.
You cant really be that making yourself that confident because its always been a challenge on handling yourself on an unpredictable market.