I've just been playing with the new functionality making small test orders, and I am quite confused how it actually works.
I started off by shorting USD.
I couldn't see this left as an open position anywhere with information about collatoral and margin requirement, but I had thought the idea was I then needed to buy USD to cancel out this 'loan', so I bought the same amount of USD. But those USD were just added to my balance - so what happened to the loan? Do I still need to repay USD at some point, and if so when?