What is a Reserve Currency?

Reserve Currency from Bretton Woods to China's Yuan

Foreign Currency
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A reserve currency is a currency held in significant quantities by governments and institutions as a means of international payment and to support the value of national currencies.

For example, Mexico issues pesos (which are essentially IOUs) to its citizens and repurchases them with U.S. dollars, euros, or other reserve currency around the world held by its central bank. Countries can also hold precious metals in their official reserves.

While these reserves used to consist mostly of gold and silver, 1944's Bretton Woods agreement expanded acceptable reserves to include the U.S. dollar and other currencies. President Richard Nixon's New Economic Policy brought an end to the Bretton Woods system in 1973, barring future major currencies from officially being converted into gold.

Reserve currencies impact monetary policies and trade around the globe.

Reserve Currency History and Future

The U.S. dollar replaced the British pound sterling as the world's premier reserve currency circa 1945 in accordance with the Bretton Woods agreements, formalizing global acknowledgment of the U.S.'s status as a leading world power. At the time, the U.S. dollar was the currency with the greatest purchasing power and the only currency backed by gold.

But, the U.S. dollar isn't the only reserve currency designated by the International Monetary Fund and other global organizations. The euro and Japanese yen have become increasingly popular as a reserve currency given the size of their respective economies, and Japan has quietly enjoyed the position of being the world's largest creditor for nearly three decades.

Countries With the Most Reserve Currency

Countries hold reserve currency for a number of different reasons. They are an important indicator of ability to repay foreign debt, to defend a national currency, and even to determine sovereign credit ratings. Also, countries may simply hold a large amount of currency due to a trade imbalance, as is the case with China and their U.S. dollar holdings.

The five countries with the most foreign reserve currency in 2018, according to the World Bank, were:

  1. China: $3.2 trillion
  2. Japan: $1.3 trillion
  3. Switzerland: $787 billion
  4. Saudi Arabia: $509 billion
  5. Russian Federation: $469 billion

China has aggressively positioned itself next in line, having been the largest contributor to world growth since 2008's global financial crisis, taking the top global exporter spot in 2009, and as the largest trading nation in the world as of 2013. Extensive investment in emerging markets in Africa, India, and now South America will likely steel their position. In fact, China's yuan was named by the International Monetary Fund as a global reserve currency in 2015.

The popularity of reserve currencies is a function of their stability and reputation. For example, the Chinese yuan hasn't taken off as a major reserve currency due to concerns over a sudden devaluation that could send their value lower. The same is true for the euro following the sovereign debt crisis in 2009 and the immigration crisis in 2016-17. These issues have led to concerns over currency volatility, which has kept the U.S. dollar as the most popular reserve currency.

Reserve Currency and Monetary Policy

Monetary policy has a strong effect on foreign currency reserves. Most major economies with flexible or floating exchange-rate schemes clear excess supply and demand by purchasing or selling reserve currency. For instance, a country looking to boost the value of its currency can repurchase its national currency with its foreign currency reserves. The Bank of Japan has been notorious for intervening in the currency markets using its foreign reserves as ammunition.

Other countries may employ fixed exchange rate schemes for a variety of reasons. Under this type of system, supply and demand can move the value of its national currency higher or lower. For example, increased demand for a national currency (e.g., due to a relatively strong economy) would lead to a higher value for its currency. It was China's preferred method to control their currency before floating the yuan to gain reserve status in the global financial system.

Countries also continuously monitor major reserve currencies to ensure their holdings aren't adversely affected. For instance, significant inflation in the U.S. could cause a devaluation of the dollar and the subsequent devaluation of foreign currency reserves. Ultimately, this limits the monetary policy benefits achievable using these reserves. In other words, there's only a margin benefit for a country's currency being considered a 'reserve' currency around the world.