...I don't know where to ask, I don't understand technical analysis; when he explains it to me I feel it's some sort of gambling strategy...
If your brother treats trading as gambling, then this is one of the red flags that he should not engage in trading, since sooner or later he will lose his money. If he takes his chosen occupation seriously, he must learn to trade in such a way that it will bring profit sufficient to meet the material needs of the family.