在任何市场中，美元指数 (USDX) 都是重要的分析工具。USDX实际是一种期货合约，这表示如果你有一个期货交易账户，你可以像交易玉米、原油、黄金以及货币期货合约一样交易它。USDX除了被用于交易，还被大多数交易者视为分析美元总体强弱的工具。
USDX是将美元 (USD) 同其他国家的一篮子货币进行对比。这个篮子代表了主要货币的加权平均数的最大自由浮动量。这个货币篮子包含欧元、日元、英镑、加元、瑞典克朗、瑞士法郎。美指会对上述每一个货币进行加权，其中欧元的比重最大。
Trading the Dollar With USDX
The US dollar index (USDX) is an important analytical tool for traders in just about any market. The USDX is actually a futures contract which means that if you have a futures trading account you could trade this instrument like corn, oil, gold or currency futures contracts. However rather than trading the USDX most retail traders use it as way to analyze the relative strength or weakness of the US Dollar in general.
The USDX compares the US dollar (USD) against a basket of other world currencies. This basket represents most of the largest free floating, major currencies in the world on a weighted average basis. The currencies included are the euro, yen, British pound, Canadian dollar, Swedish krona and Swiss franc. Each of these currencies are given a weight within the index with the largest weight given to the euro.
The euro is typically half the total weight included in the average the chart for the USDX and will often look like a chart of the USD/EUR futures contract. Spot forex traders will notice that the USDX is very similar to an inverse of the EUR/USD spot forex pair. However, because the USDX includes 6 different currencies it is a better measure of USD strength than any single currency pair including the EUR/USD.
The USDX was established in 1973 with a starting value of 100. That means that if the USDX is measuring less than 100 the USD has lost relative value compared to what it was worth in 1973 and if it is above 100 then the USD is stronger than it was in 1973. Currently the USDX is hovering around 82, which means that it is 18% weaker than its starting value. The dollar has not always been weaker than it was in 1973, the USDX showed a 20% improvement in value in the USD in 2001 and 2002.
The USDX is particularly useful for traders in the bond, currency and gold markets. For example, a strong USD is usually correlated with falling gold prices, which means that gold traders are very interested in a break out on the USDX even though they may not be trading the USD directly. Similarly, global crises often increase demand for the USD as investors seek a shelter from uncertainty. This will drive the value of the USD up and often bond yields will drop. These are just two examples of how the USDX is one more inter-market tool you can use for evaluating capital flows and finding new trading opportunities.
Charts for the USDX on the pairs analysis pages in the forex section of the Learning Markets website but if you are interested in trading the USDX you have two attractive alternatives. First, you can open a futures account. There are futures and options on futures available on the USDX that trade on the New York Board of Trade.
Second you can trade ETFs that track the USDX itself. PowerShares offers two ETF alternatives for trading the index.