In macroeconomics, money supply (or money stock) refers to the total volume of money held by the public at a particular point in time. There are several ways to define "money", but standard measures usually include currency in circulation (i.e. physical cash) and demand deposits (depositors' easily accessed assets on the books of financial institutions). Money supply data is recorded and published, usually by the national statistical agency or the central bank of the country. Empirical money supply measures are usually named M1, M2, M3, etc., according to how wide a definition of money they embrace. The precise definitions vary from country to country, in part depending on national financial institutional traditions.
Even for narrow aggregates like M1, by far the largest part of the money supply consists of deposits in commercial banks, whereas currency (banknotes and coins) issued by central banks only makes up a small part of the total money supply in modern economies. The public's demand for currency and bank deposits and commercial banks' supply of loans are consequently important determinants of money supply changes. As these decisions are influenced by central banks' monetary policy, not least their setting of interest rates, the money supply is ultimately determined by complex interactions between non-banks, commercial banks and central banks.
