I am fairly new to investing and for nearly 12 months now, have invested money in the stockmarket. I put $80k of my own money and borrowed $40k for a margin loan. It was fixed for 3 years at 9.4%. With the poor state of the economy at the moment and interest rates going down I am starting to wonder if this margin loan was worth it. Can I repay the principle on the loan whenever I want? Will this reduce the amount of interest I have to pay (currently $3800p.a. upfront)?