But that's not how money works. Banks don't loan money they have on deposit. They loan money they create from thin air, and are required to have a certain amount of deposits to potentially cover that if their exchanges with another bank become too imbalanced. That's what's called "leverage."

I don't see how what you said conflicts with what isostatic said at all.

Then either corporations can hoard all the money, leaving less for the rest of us, or banks can create money from thin air, in which case there's no practical limit and hoarding doesn't matter.

Ah, I see. Good point.

I think investment is actually a measured variable.