European Currency Unit opportunity for foreign diversification without reliance on the currency of a single country. The ECU was conceived on 13 March 1979 as an internal accounting unit. It had the ISO 4217 currency code XEU. On 1 January 1999, the euro (with the code EUR and symbol €) replaced the ECU, at the value €1 = 1 ECU. Unlike the ECU, the euro is a real currency, although not all member states participate (for details on euro membership see Eurozone). Two of the countries in the ECU basket of currencies, UK and Denmark, did not join the eurozone, and a third,
International status and usage of the euro is attractive for international transactions when it demonstrates stability, a well-developed financial market to trade the currency, and acceptability to others. While the euro has made substantial progress, a few challenges undermine the ascension of the euro as a major reserve currency. Persistent excessive budget deficits of some member nations, economically weak new members, conservatism of financial markets, and inertia or path dependence are important factors keeping the euro as a junior international currency to the US dollar. However, at the same time, the USD has increasingly suffered from a double deficit and has its own concerns. As the euro