fidelity tells me unsettled amount = 0 and my account value/spending limit has been increased the only thing that doesn't change is my margin balance. let me try to ask the question in another way if I have $10 cash when I opened my account, and I purchased $1 worth of stocks using "margin," not "cash," do I pay interests on the $1 I spent? the main concern I have is whether the cash I have is just used as a security deposit for my credit account (margin) for my borrowing power or it can actually offset my debt in the credit account.