The setup of the banking system under the Empire allowed the exchange of extremely large sums without the physical transfer of coins, which led to fiat money. With no central bank, a professional deposit banker ("argentarius," "coactor argentarius", or later "nummularius") received and held deposits for a fixed or indefinite term and lent money to third parties. Generally, available capital exceeded the amount needed by borrowers and so loans were made and credit was extended on risky terms. The senatorial elite were involved heavily in private lending, as both creditors and borrowers, and made loans from their personal fortunes on the basis of social connections.