The proof-of-stake is a method of securing a cryptocurrency network and achieving distributed consensus through requesting users to show ownership of a certain amount of currency. It is different from proof-of-work systems that run difficult hashing algorithms to validate electronic transactions. The scheme is largely dependent on the coin, and there's currently no standard form of it. Some cryptocurrencies use a combined proof-of-work/proof-of-stake scheme.
The Money Market enables the commercial banks to use their excess reserves in profitable investment. The main objective of the commercial banks is to earn income from its reserves as well as maintain liquidity to meet the uncertain cash demand of the depositors. In the money market, the excess reserves of the commercial banks are invested in near-money assets (e.g., short-term bills of exchange), which are easily converted into cash. Thus, commercial banks earn profits without sacrificing liquidity.