What is the economic tool used by the federal reserve to buy or sell US treasury bonds?

The economic tool used by the Federal Reserve to buy or sell U.S. Treasury bonds is called open market operations. Through these operations, the Fed can influence the money supply and interest rates in the economy. When the Fed buys Treasury bonds, it injects money into the banking system, lowering interest rates; conversely, selling bonds withdraws money, raising interest rates. This tool is a key mechanism for implementing monetary policy.