I'm new to using IB and I'm having trouble understanding how IB handles margin. I'n not exactly sure how to phrase this question so I will give an example. I'm curently long 4400 shares of QQQ. initial margin requirement $92,003 maintance margin requirement $55,202 stock market value $184,007 cash balance $-92,519 equity with loan value $91,448 net liquidating value $91,448 what I dont understand is why with the above account, I can't buy any more stock on the following day? It tell's me initial margin requirement with new position will be greater then equity with loan value. Does that mean I can never open a position and go above 2:1 margin? What's the point of maintenace margin then? In my other account at Southwest securities, this exact position would give me excess equity of $36,246($91,448-$55,202) x2 =$72,492 to trade with for the following day. If this is how IB really uses margin I will have to find a new broker.