Free market capitalism and full employment of capital resources is the return on that promotion of the general welfare investment.
When productive capitalism gives way to monopoly capitalism, a new brand of parasite is born:
MR Online | Notes on Marx’s “General Law of Capitalist Accumulation”
"Before long, too, the system breeds a new species: Marx labels them 'a new financial aristocracy, a new variety of parasites in the shape of promoters, speculators and nominal directors,
a whole system of swindling and cheating by means of corporation promotion, stock issuance, and stock speculation.'
"Could Marx be talking about us?
"By God yes.
"Nowadays, we know these people by name, by sleazy reputation; we know, too, that within the overall accumulation process this new financial aristocracy has a stake very different to that of productive capital’s."