There is one thing I see new traders do consistently, and it doesn't matter who it is or what they trade, I see it ALL THE TIME.
1 - They get comfortable
2 - They start taking bigger and bigger positions
3 - They defend their large sizes by coming up with "risk management"
4 - They take a loss that should be small under normal conditions, and it ruins their month/year/account
I see it so often, I wish I could start a brokerage that gave out fat discounts like free trading period. That way, I could design a system that monitored trades and found when traders enter this stage. At that point, my system would automatically take the opposite side of every trade.
Unfortunately, I never see a trader admit or listen to me when I tell them they are doing the above. But after the fact, they see it, unfortunately. I've noticed people want to learn and see it for themselves rather than listen to advice, precisely why most men suck with women too