A nice idea, though quite unsure whether this would fuel the price for a push given that Wall Street's involvement with crypto is already there, we just don't know how "involved" these institutional investors are or whether they'd be interested to get involved deeper. Linking the money of Wall Street to crypto means that the government would surely make some regulations to benefit their end; definite taxation rules regarding crypto would just linger around the corner, and the crypto market would 'mature' since it would be highly regulated in case Wall Street dived into it fully.
I do not think they would be able to do this. Especially in the light of G20 current regulatory status - where any ICOs in United States are prohibited...
I think this would be a different scheme, or could just be another exchange or another broker which would just make things for these institutional investors
easier to put their money on the crypto market.