I've always traded in a cash account. Now that I've become more confident in my trading style I'd like to bring in some modest leverage... Say I have a margin account with $25,000 at IB. This gives me 2x buying power. If I buy $30,000 worth of stock and hold the positions for a couple months... where does the $$$ come to pay monthly fees + margin interest? Basically I'm wondering once my 25k is in use and I'm dipping into margin to trade where does the money come for fees, interest and commissions? Thanks and please let me know if you want me to clarify any part of my question.