However, these things are not really a good idea...you'll say that you are a good trader which I supposed to think that you can make money pretty easy in trading and could multiply it.
What more can I say? Better do his own business and not use someone else's funds. It will make his life a mess. If what he is claiming is true, being a good trader, there's no need to get money from his friend. As this will be the start of his problems in trading. He should focus on his own account and not be bothered by other things. I don't see any reason accepting someone else's money if you are already doing good on what you do.
Its something logical or even a common sense thing to be done and as been reasoned that he do look for more funds to extent out his capital then he can make it on his own since he's a profitable trader and its true
that when you handle out someones money then thats already a burden thing to add up into your stress and doubts since you do know that you do need to pay them up some interest of their funds and thats a
stressful thing on my side and it would be much better if you do only trade up with your own money since you do know that in case things do come opposite or turn upside down then you wouldnt worry too much
since no one will able to sue or blame you out incase that thing do happen.