Since 200 1, the US dollar index, which reflects the exchange rate changes of the US dollar against major western currencies, has formed an obvious downward trend. The US dollar index dropped from 12 1.02 in early July 20065438 to the lowest point of 84.42 in February 2004, with a cumulative decline of 33.54%. In fact, the strong dollar no longer exists. At present, global commodity trading is still dominated by US dollars, which accounts for about 70% of global foreign exchange reserves. The trend of US dollar exchange rate has an important influence on commodity trading market, futures market and the redistribution pattern of economic interests of various countries. We will analyze and judge the medium-term trend pattern of the US dollar from the leading factors and market fluctuation characteristics of the previous large fluctuations of the US dollar index, and discuss its influence on the futures price trend of the basic metal market.

First, the leading factors of the sharp fluctuation of the US dollar index

In the past 30 years, the dollar has experienced two crises. The first crisis broke out between 1973- 1976, which was marked by the complete decoupling of the dollar from gold and the collapse of the Bretton Woods system. The second crisis broke out between 1985- 1987, which was marked by the signing of the Plaza Accord and the collapse of the American stock market. On the surface, this round of dollar adjustment of 200 1 is the result of the adjustment of the "strong dollar policy" pursued by the Bush administration to the Democratic government after the mid-1990s. Si Nuo, the current US Treasury Secretary, made a speech on "Strong Dollar Policy" at the meeting of finance ministers of the Group of Seven, which is widely regarded as a signal that the United States is pursuing a weak dollar policy. Behind the policy changes, economic factors are still at work. According to Goldman Sachs' forecast, the budget deficit of the United States in the next 10 year will reach 5.5 trillion US dollars, and the trade deficit under the current account will exceed 5% of GDP. The continuation of the situation in twin deficits is the basis for the weakening of the dollar policy. What's more, the US dollar interest rate is at its lowest point in 45 years. Low interest rates and the US war on terrorism have led to the reversal of international capital inflows, making it difficult to make up for the balance of payments deficit. On the whole, twin deficits, low interest rates and terrorist attacks lead to international capital outflows, which are the basic reasons for the mid-term depreciation trend of the US dollar. Compared with the dominant factor of the three-time intermediate adjustment trend of the US dollar, the international capital flow caused by the development difference of the main economic growth forces and the change of exchange rate mechanism caused by it are the main reasons. Every industrial transfer and the emergence of emerging strong growth regions mean the redistribution of monetary interests, which is finally reflected in the formation of a new exchange rate mechanism. The change of RMB exchange rate mechanism will prompt this round of adjustment to be completed as soon as possible.

Second, the characteristics of the mid-term market volatility of the US dollar index

According to the statistical analysis of relevant people, in the mid-term fluctuations of the US dollar market in the past 30 years, every round of ups and downs of the US dollar has certain regularity and periodicity-the average duration of each round of ups and downs is about 5-7 years. According to past statistics, in the past 30 years, there have been about 17 significant contrarian pullbacks or rebounds of the US dollar index, of which 10 bounces or pullbacks exceeded 10% (relative to the general trend of the cycle). The above statistical analysis shows that there is a contrarian rebound or rebound with a significant amplitude exceeding 5% but less than 10% every two years, and there is a contrarian callback or rebound with an amplitude exceeding 10% every three years. This remarkable contrarian secondary fluctuation with fluctuation amplitude exceeding 10% can be regarded as a correction wave in wave theory. According to the wave theory analysis, the mid-term adjustment trend of the US dollar launched on 200 1+02 1.02 has finished the third phase of the main decline. Because of the extension of the third period, the low point of the next callback is still in the area of 84-85. Since the 80-85 region of the US dollar index is the bottom region for more than 20 years, once it is broken down, it will have a destructive impact on the stability of the world financial system, so the joint intervention of the government is inevitable, and this region still has a strong supporting role in the past two years. It is necessary to pay attention to whether the dollar has a significant contrarian correction as expected: first, whether there are signs of change in the spread factor; Second, whether there has been a positive change in the security situation against terrorism; Third, whether there are signs of improvement in the balance of payments situation caused by twin deficits; The changes of the above three factors will determine the strength and way of market contrarian correction.