NB: So is socialism.
There is no justification for an economic system that allows for unbridled avarice. We rightfully prosecute other sins, such as theft, murder, libel, and many others. Why would extreme avarice be any different? It's not good for the greedy man, nor is it good for society. There is no justification for it from Christ, the apostles, or anywhere. In fact, we see quite the opposite.
Given these moral precepts, why do we allow billionaires to have billions in dollars while the poor go without food and shelter? Why do we allow usury, when that is condemned repeatedly and aggressively throughout the Bible?
We do have a right to property, and we certainly have a right to invest as we see fit. That said, we do not have a right to hoard as much property as we like and neglect the needs of the poor. Such an idea is a corruption of Christianity and has no basis in good theology.