Primary Dealers

Primary dealers are banks or securities broker-dealers who may trade directly with the Federal Reserve System of the United States. They are required to make bids or offers when the Fed conducts open market operations, provide information to the Fed's open market trading desk, and to actively participate in  U.S. Treasury securities auctions. They consult with both the U.S. Treasury and the Fed about funding the budget deficit and implementing monetary policy. Many former employees of primary dealers work at the Treasury, because of their expertise in the government debt markets, though the Fed avoids a similar revolving door policy.
See more at Wikipedia.org...

Security firms that are recognized by the U.S. Federal Reserve System to buy and sell securities with the Fed.