From the Fed’s website:

  • In general, these swaps involve two transactions. When a foreign central bank draws on its swap line with the Federal Reserve, the foreign central bank sells a specified amount of its currency to the Federal Reserve in exchange for dollars at the prevailing market exchange rate. The Federal Reserve holds the foreign currency in an account at the foreign central bank. The dollars that the Federal Reserve provides are deposited in an account that the foreign central bank maintains at the Federal Reserve Bank of New York. At the same time, the Federal Reserve and the foreign central bank enter into a binding agreement for a second transaction that obligates the foreign central bank to buy back its currency on a specified future date at the same exchange rate. The second transaction unwinds the first. At the conclusion of the second transaction, the foreign central bank pays interest, at a market-based rate, to the Federal Reserve. Dollar liquidity swaps have maturities ranging from overnight to three months.

    When the foreign central bank loans the dollars it obtains by drawing on its swap line to institutions in its jurisdiction, the dollars are transferred from the foreign central bank’s account at the Federal Reserve to the account of the bank that the borrowing institution uses to clear its dollar transactions. The foreign central bank remains obligated to return the dollars to the Federal Reserve under the terms of the agreement, and the Federal Reserve is not a counterparty to the loan extended by the foreign central bank. The foreign central bank bears the credit risk associated with the loans it makes to institutions in its jurisdiction.

    The foreign currency that the Federal Reserve acquires is an asset on the Federal Reserve’s balance sheet. Because the swap is unwound at the same exchange rate that is used in the initial draw, the dollar value of the asset is not affected by changes in the market exchange rate. The dollar funds deposited in the accounts that foreign central banks maintains at the Federal Reserve Bank of New York are a Federal Reserve liability.