Ameritrade has a policy against buying many China small caps without placing the order over the phone, and they were never able to explain why... other than to say that many of them are thinly traded (no kidding)and could be manipulated. It's why I left them years ago.
But they'd let you buy all the ENRON you wanted at it's all time highs I'm sure, because it wasn't Chinese, lol.
For China small caps, AMTD is probably the worst brokerage to use.
SGZH...Tried to buy thru Ameritrade online...can not do so...called and was told they were advised by Security agencies stock should be bot only thru a Broker...
They will give you the internet commission...even though a broker must place it...