I personally think that greedy human is ridiculous. Those who there is only money in their head are not good humans. In university my teacher told me that we need to make biggest profit using smallest cost, this statement is right but it doesn't mean that we ignore our common sense to prioritize humanity. I sell bitcoin only there is a very strong signal that I have to sell but holding is also good if I want it for long term. That's why I don't easily sell my btc, probably I only sell every 3 - 6 months and it's enough for me to make profit.