My own experience and opinion is that when you buy any coin or token,when you know that it well pump in coming days, and the coin or token start dumping . Than you loose your patience and panic to sell
Not everyone. When you buys a coin, and was expecting it to pump, and then the price start falling. You don't have to loose you patience and sell. What if after falling, the price then start pumping, won't you regret selling at a lower price? You will definitely regret your actions. Although, some people are not patience enough when it comes to holding of coin. Especially Newbie, they are always afraid of losing their funds.
I believe most people sell because they believe bitcoin will definitely dump so they don't want it to be dump on them so they sell when the price is high and buy back when the price is low, after getting to all time high people don't really believe bitcoin will break the all time high they are scared of dump so they will sell.
Bitcoin price do rises and falls. When the price dump,I think it should be an opportunity of acquiring more of it, rather than selling the ones you already have. However, some people are probably afraid of dump, so they end up losing on their Investment, instead of making profits.