As for me, it's still better to set a target goal and sell when you have reached it. Sometimes, greediness could take everything from us. Reaching our target profit is more than enough because profit is still profit no matter how big or small it is.
Every market relies on the actions that the traders in that market takes (human psychology as we usually do see), but how do you know when people are in a particular state of mind? You can’t even tell when and how, so what makes you so sure that it is easy to trade cryptocurrencies? It is not.
Anyone can decide to sell at anytime and that doesn’t determine their mood at that moment, it can just be that what they want to do at that moment is to sell due to they need that money for something else. So you’re totally wrong, the way you have put it is not how it’s going to be working.