a friend is investing dollars and euro. but he is making so many funny moves that he really earns very little. another friend earn much more thanks to his courage even though he does not know the market well.
Your friend is just lucky, it is true that you need guts in order to be an investor but that is not enough you need to have knowledge because once the luck runs out and your friend begins to lose money it is likely he is going to take even greater risks trying to keep his previous earnings and when he does that he will lose even more money as a result of his decisions.