Interest for CFD and SSF???

[#1]

Hi, I just would like to know on which amount interest is calculated? For example if I buy R 100 000.00 worth of SSF or CFD and gearing is 5, I pay R20 000.00. If gearing is, say 2 I will pay R 50 000.00. Is the interest now charged on the R 100 000.00 or the loan amount R 80 000/R 50 000. Need to know this in making decisions for longer term derivatives views.....

[SimonPB]

you pay on the full loan amount, and you then earn interest on the margin ..