Every other institution borrows long to lend short. That's how money is usually made in a financial company, like a hedge fund or something similar. Banks are

Every other institution borrows long to lend short. That's how money is usually made in a financial company, like a hedge fund or something similar. Banks are the counterparty (in a cosmic sense) to that trade: they borrow short to lend long. It is an inherently unstable business model, but it works if you trust them enough.