Most traders always think that acquiring the skill of trading will reduce the losses,yeah it's right a trader knows the fundamental and technical analysis of trading.But a greedy trader may end up with losses most times for instance a trader targeting a profit of 100% and when the profit is 50% he/she won't sell the current profit and when the price drops the trader regrets and loss.And also a trader should trade an amount he/she can afford to lose in order to reduce great loss.