It does seem that if there's no way to buy from the USA that there's a hell of a business opportunity there. I know nothing about this, but if that gap exists and anyone wants to work on the problem together... let's do this?
The business opportunity exists in helping mainland investors move their money outside China.
Matching those that want to invest in China and those moving their money outside happens already, mainly via internet banking exchange of passwords and sufficient trust in the middle-man. It is legal (it is not legal to swap passwords, this is a simplification, but the crux of it), but an authorized exchange of ownership of back accounts.
I work in this space, the only way to get exposure to these is via equity swap using a QFII's capital. I.e. you must be a foreign institutional investor with an existing relationship to a QFII. Retail flow is not supported :) (although thats kind of what north bound stock connect is for).
