All investments will be meaningless with AGI. Having full AGI would mean infinite supply of physical and mental labour. Cost of everything should tend to zero unless some greedy people believe that they should have bigger share of resources then others.

Atleast the rich are somewhat better at managing money as of now. Making a good argument for the existence of such great wealth differences. But in a world where an AI is better then everything else would it even make sense to have some with so much more