Quote Originally Posted by mingpan.lam View Post
Thks Rembert,my account is HKD, so I am thinking if I should change it and to minimize the interest to pay.
Yes the same is true if your account's main currency is HKD. At the moment the interest rate for borrowing USD at IB is 1.56%
http://www.interactivebrokers.com/en/p.php?f=interest

One could argue it's best to buy USD so one doesn't have to pay this interest. But when the dollar crashes relative to HKD or EUR we will lose a lot more than 1.56%. That's why I'm keeping the account in EUR for now.

I'm no Forex trader. But if there was a reliable robot that could switch between EUR/USD I'd make use of it. Maybe there is such a robot out there, I don't know ... google shows a lot of results for forex robots, but I'm willing to bet 95% of them are scams.