In November 2011, the Fed approved new swap lines with Canada and the aforementioned countries. These are bilateral agreements between the six banks to ensure that their countries have a sufficient number of currencies. In October 2013, central banks concluded the agreements in a sustainable manner until further notice. Avatars of later lines of currency sweats first appeared between 1880 and 1920, when central banks exchanged gold reserves as needed; But the first effective swea-currency lines (between eight central banks) were created in the 1960s: they were activated and used by three jurisdictions, the Bank of England, the Bank of Canada and the United States. [3] Swap lines were briefly reintroduced after the 11th, but did not gain global importance until the beginning of the credit crunch. [4] In May 2010, the FOMC announced that, in response to the resurgence of tensions in short-term dollar financing markets, it had authorized dollar liquidity swaps with the Bank of Canada, the Bank of England, the European Central Bank, the Bank of Japan and the Swiss National Bank. In October 2013, the Federal Reserve and these central banks announced that their existing temporary liquidity exchange agreements, including dollar liquidity exchange lines, will be converted into permanent agreements that will be maintained until further notice. Since October 31, 2013, the Federal Reserve has also established dollar liquidity exchange lines with the Bank of Canada, the Bank of England, the Bank of Japan, the European Central Bank and the Swiss National Bank. In particular, two types of liquidity exchange lines have been put in place to improve liquidity conditions in U.S. and foreign money markets in times of market stress: U.S. dollar liquidity exchange operations — by country The Fed has already entered into permanent trade agreements with the Bank of Canada, the Bank of England , the European Central Bank, the Bank of Japan and the Swiss National Bank. Other major economies such as India, China, Russia, Saudi Arabia and South Africa – all parts of the G20 – do not have a swap line with the United States.