I think the top reason why traders are failed in trading is greedy,inpatients, lack of knowledge and no have yet experience in trading.I know that trading is basically buy low and sell high.but not just to think.it needs to view the project of you're coin that you trade that's why many traders have loss.its just because they don't know the project of coin if good future or not.
Most of the traders today are failing because they are all impatient, most of them tend to sell their coins at the lowest price when the market is dumping its price and from there they are losing a huge amount of their investments.
The advice of buy low and sell high is always the first one that would be given when someone ask what to do in trading and how to profit in it but even though it is the most basic, many traders cannot still follow it and often times do the opposite which is buy high and sell low resulting to more losses. When a coin is hype and it already has a high price, some would immediately buy thinking that it would continue to rise and then the coin would dump and the one who bought has already an unrealized loss and be discouraged of the price selling it at a low price which would lead to a realized loss. This would continue until such time one learns his lesson and have a trading plan and risk management.