Use as reserve currency

Since its introduction, the euro has been the second most widely held international reserve currency after the U.S. dollar.The share of the euro as a reserve currency has increased from 17.9% in 1999 to 26.5% in 2008, at the expense of the U.S. dollar (its share fell from 70.9% to 64.0% in the same timeframe) and the Yen (it fell from 6.4% to 3.3%). The euro inherited and built on the status of the second most important reserve currency from the German mark. The euro remains underweight as a reserve currency in advanced economies while overweight in emerging and developing economies: according to the IMF the total of euros held as a reserve in the world at the end of 2008 was equal to USD 1.1 trillion, with a share of 22% of all currency reserves in advanced economies, but a total of 31% of all currency reserves in emerging and developing economies.

The possibility of the euro becoming the first international reserve currency is now widely debated among economists. Former Federal Reserve Chairman Alan Greenspan gave his opinion in September 2007 that it is "absolutely conceivable that the euro will replace the dollar as reserve currency, or will be traded as an equally important reserve currency." In contrast to Greenspan's 2007 assessment the euro's increase in the share of the worldwide currency reserve basket has slowed considerably since the year 2007 and since the beginning of the worldwide credit crunch related recession and sovereign debt crisis.