Quote from yip1997:
I believe you have to pay tax for the performance fee received from trading OPM.
Your friend can deduct the advisor fee.
Does your friend's profit reported in 1099 from the brokerage firm is the net profit (i.e. profit - advisor fee paid to you if it is automatically charged as in IB advisor account)?
The only tax consequence is that of my friend based on the gains and this is an IRA account. I do not take any money for trading his money; there is no "advisor fee" or any other financial incentive for me. I do it at no cost because he's a long time friend and I'm merely mirroring my trades by buying (selling) the same stuff in his account.

This is very useful!