Fidelity now allows international trading and now therefore allows you to hold foreign currency in your account for the sake of trading foreign markets. So I have 2 questions, 1) Is this a good way to buy foreign currency? 2) If I were to buy some Hong Kong Dollar, is that a pretty good proxy for the Chinese RMB?
I don't know about #1, but if you're trying to get exposure to the Chinese economy in forex, your best bet would be AUD in my opinion.