We can never truly tell when it is the right time to sell and even if we set a target based on our assumed ath there is no assurance that it will be hit. So it is very hard to sell at the very top. What we can just do is that trust the project where we have invested and that it will reach our desired market cap. We can also try to analyze the market through technical anaylsis for much better making of decisions.

And I believe most of us have that experience where we did not sell because in our mind it will still go up. Yeah I have that experience too and I've lost some profit. I was a newbie that time and don't know a lot about technical analysis and trading stuff and did a lot of mistakes as well but what important is that I learned from it.