A periodic reminder that Scrooge McDuck does not actually hoard his wealth in a vault. He's too greedy to do that, because he wants his money to make more money.
So he loans it out to other people for a fee so they can use it for various purposes of their own. His greed drives him to be financially helpful to others.
It's Smithian. He's doing it out of self-interest, not benevolence or generosity, but it works to everyone's benefit.