Quantitative easing (QE) is a monetary policy used by central banks to stimulate the economy when standard monetary policy has become ineffective. A central bank implements quantitative easing by buying financial assets from commercial banks and other financial institutions, thus raising the prices of those financial assets and lowering their yield, while simultaneously increasing the money supply. This differs from the more usual policy of buying or selling short-term government bonds to keep interbank interest rates at a specified target value.