Well most of the time you lose money because your interest and your broker%u2019s interest are not the same, they are always in conflict. Your broker%u2019s interest lies in earning more and more brokerage from you and that is possible only if you trade as frequently as possible. Therefore, his interest lies in making you trade more and more often, this is known as %u201Cchurning%u201D. It doesn%u2019t matter to him whether you make profits or losses, he is happy as long as he can get his commission out of you. Whereas, your interest lies in trading less number of times, making trades only when there is the best chance of profit and holding your positions for longer time periods. Your broker CANNOT have your interest in his heart, he has his own interest in his heart, which is natural. So your broker cannot be your fair advisor. He is biased against your interests because he has to be loyal towards his own interest. So when you trade purely on the advice of your broker, specially in the derivatives market, you are bound to lose more money than you make in it.
