Reserve currency economy, the German Deutsche Mark gained the status of the second most important reserve currency after the US dollar. When the euro was introduced on 1 January 1999, replacing the Mark, French franc and ten other European currencies, it inherited the status of a major reserve currency from the Mark. Since then, its contribution to official reserves has risen continually as banks seek to diversify their reserves, and trade in the eurozone continues to expand. Former U.S. Federal Reserve Chairman Alan Greenspan said in September 2007 that the euro could replace the U.S. dollar as the world's primary reserve currency.
Currency pair = Cable = GBP/USD. The currency pairs that do not involve USD are called "cross currency pairs", such as GBP/JPY. Pairs that involve the euro are often called "euro crosses", such as EUR/GBP. Currencies are traded in fixed contract sizes, specifically called lot sizes, or multiples thereof. The standard lot size is 100,000 units. Many retail trading firms also offer 10,000-unit (mini lot) trading accounts and a few even 1,000-unit (micro lot). The officially quoted rate is a spot price. In a trading market however, currencies are offered for sale at an offering price (the "ask price"), and traders looking