Quantitative easing (QE) is an unconventional monetary policy tool used by some central banks to stimulate the national economy when conventional monetary policy has become ineffective. A central bank implements quantitative easing by purchasing financial assets from banks and other private sector businesses with newly created money. This action increases the excess reserves of the banks, and also raises the prices of the financial assets bought, which lowers their yield.

                                                                                                     ——from wikipedia