There are a lot of reasons why fx traders lost so much, these can be categorised as reasons of traders' personality, and the systems they deployed. It is a very difficult business as well as a very easy one in trading. The hardest part is to develop a robust trading system which suite his/her personality and trading style and stick with the trading rules religiously. There is never a one trading system fit all as such in this business. A lot of trading systems, indicators are junkies anyway. The only thing that really works in the forex market is the price, volume and time (the cycle). If a trader's trading system build around these concepts then his/her chances of succeeding are high.