 A dramatic increase in the velocity of money as the cause of hyperinflation is central to the "crisis of confidence" model of hyperinflation, where the risk premium that sellers demand for the paper currency over the nominal value grows rapidly.The second theory is that there is first a radical increase in the amount of circulating medium, which can be called the "monetary model" of hyperinflation.In either model, the second effect then follows from the first—either too little confidence forcing an increase in the money supply, or too much money destroying confidence.