getting too attached to your coin. the best traders cut their losses, and quick at that
This is a very common problem that I see as well, some people get in love with a coin and they decide to hold no matter what, the only coin that you should hold no matter what is bitcoin, every other coin should be up for sale if the circumstances are right, or if you see that the coin is going down and it's not going down just because of the speculation, it's going down because something terrible happened.