Are you a successful trader yourself? I cannot imagine anyone preferring to work for someone else vs. working for themselves given the same income. Perhaps for a young person, going to work every day would be exciting and its important to be around other people. But if you found success in trading yourself, then this would be the better road. A career in finance, or being a "professional" trader is nothing like being a retail trader I imagine. I am also almost inclined to say that if a trader is struggling, then going pro is the reasonable choice, but if you know how the markets work, might as well just make money from the comfort of your own home without a boss or all the other issues that come with employment.
The typical "Wall Street" business is composed of Sales, Trading, Research and Operations ( Ops for short.) It sounds like your brother is behind the curve, if he has to take advice from you. Tell him to research leading firms that have the products that interest him the most. Then, see what positions he can qualify for among the key functions. If he can get in, he can build up his skill set to pursue the career track that he wants. The key is to get into one of these areas. To be practical, you have to be in a State with a financial industry to begin with. Otherwise, it's back to school for 6 or more accounting credit hours and in order to get a corporate financial management job. This is where CFO's come from. There is also entry-level lending in the consumer, asset-backed (inventory) and corporate leasing areas. He can become a lender (sales) or an underwriter (research) or a loan processor (operations).
What constitutes "successful" trading ? Ultimately, the randomness of short term price movements and limbic system burnout will propel one onto the heap of failed trader statistics. Have him develop a longer term view utilizing robust , empirically tested methods.
In my opinion, trading is a kind of job. There will be risk than others but the profit it brings can be
Thank you very much, guys, you really opened my eyes in some questions! I understand that it's pretty hard to find a good job in this field, I will share your's thoughts with him, one more time thanks a lot!