I tried on simulated account to buy 1 BRR future (multiplier = 5).
Total amount with commissions expected was 49280
Initial margin expected was +31047
Maintenance margin expected was +24837
Actual order fill price was 9855.
But the cash subtracted from my account was only $25. How is this number calculated? Does it mean I borrowed $49255 and should I pay interest rate on it? If so, which rate?
I expected Initial margin to be subtracted from my cash balance but it wasn't!