Another fierce mistake most people do while trading or investing on bitcoin is that they got carried away whenever there's a bullrun, thinking that the all time high in price will maintain that same high and keep increasing which is obviously not it at all, bit i can still define such as not been experienced enough to have studied the volatility nature, there are many strategies use to cut cost, loss and take the gain, just as simple as knowing when to set in and pull out, also some got engaged into altcoins as well, forgetting the mere volatile can cost the other crypto to fail.