When the Fed sells bonds in open-market operations, it decreases the money supply.
If the Fed raises the reserve requirement, the money supply decreases
If the Fed wants to increase the money supply, it can decrease the interest rate it pays on reserves.
When the FOMC increases its target for the federal funds rate, the money supply will decrease
If bankers decide to hold more excess reserves because they are fearful of bank runs, the money supply decrease.
If the Fed wants to increase the money supply, it can buy bonds in open-market operations.
If the Fed reduces the reserve requirement, the money supply increases.
When the Fed decreases the interest rate it pays on reserves, the money supply will increase.
When the FOMC decreases its target for the federal funds rate, the money supply will increase.
When Citibank repays a loan it had previously taken from the Fed, it decreases the money supply.