Only seasoned traders know that defense wins the game. Every year, every month, or every week, or every day, there are traders jumping out to say he gained 500%. I believe them, they can do that, but I don't believe they can do it consistently for a long period of time.
If trading becomes gambling, why not just go buy lottery ticket. There is always one guy that spend $1 and wins $50 million. Than's 5000000000% return in few days.