Monetary aggregates, known also as "money supply", is the quantity of currency available within the economy to purchase goods and services. Depending on the degree of liquidity chosen to define an asset as money, various monetary aggregates are distinguished: M0, M1, M2, M3, M4, etc. Not all of them are used by every country. Note that methodology of calculating money supply varies between countries. M2 is a monetary aggregate that includes all physical currency circulating in the economy (banknotes and coins), operational deposits in central bank, money in current accounts, saving accounts, money market deposits and small certificates of deposit. Excess money supply growth potentially can cause inflation and generate fears that the government may tighten money growth by allowing the interest rates to rise which in turn, lowers future prices. M2 = Currency in circulation + demand deposits (private sector) + time and savings deposits (private sector).
A higher than expected reading should be taken as positive/bullish for the CNY, while a lower than expected reading should be taken as negative/bearish for the CNY.