Uggghhh. Zerohedge!. Is there anything they understand before they weigh in on a topic? The Fed began to pay a small interest on reserves during the financial crisis in order to put a floor under the Funds Rate and hold it above zero. As long as there are net excess reserves, the funds rate, which is a negotiated rate among banks, will plummet rapidly toward zero if no interest is paid on excess reserves. The Fed normally uses reserve balances to target a funds rate, which you can think of as the wholesale price of money for banks. When there are excess reserves the Fed would typically drain them by selling Treasuries. However during the Banking Crisis and QE they were net buying Treasuries while demand for Credit was drying up. The Fed intended to drive rates down dramatically, but they wanted to maintain a wholesale rate slightly above zero. To prevent rates from going all the way to zero in the face of swollen reserves and QE the Fed decided to pay a small interest on reserves. Even though the Fed is now both tightening and unwinding they may need to continue paying interest on excess reserves for a considerable time (years) as a part of their mechanism for targeting a Funds Rate. Let us not lose sight of the magnitude of the Great Recession, it was a calamity of gigantic proportions.
Note that there are other mechanisms that can be used to maintain a target price for bank money other than the reserve requirement adopted by the U.S. Central Bank. See, for example, Canadian or Australian Central Bank operation. Also please note the too common use of unlabeled axes in Zerohedge Graphs. The best advice I could give anyone is never bother to read a zerohedge article on anything. They are way too often a pernicious intermingling of truth and untruth . I wonder if their parent organization is headquartered in St. Petersburg.)