2. Economic performance of major economies such as Europe and Japan. The level of the dollar index depends not only on the economic operation of the United States itself, but also on the comparison between the American economy and western economies such as Europe and Japan. Therefore, when analyzing the dollar index, we should not only pay attention to the American economy, but also pay attention to the comparison between the American economy and the European and Japanese economies. If the US economy deteriorates and the European economy improves, the US dollar index will drop; If the economic situation in the United States improves, the economic situation in Europe and Japan deteriorates, and the dollar index rises; If the economies of the United States, Europe and Japan deteriorate at the same time, as long as the economies of Europe and Japan decline faster than those of the United States, the dollar index will also rise.
3. The need for investors to preserve their value. Although the dollar has been depreciating for a long time, it is still the current world currency, and its international currency status is difficult to change in the short term. Therefore, in the context of the continued depreciation of other currencies in the world, the US dollar is still the best means of maintaining value. Although the employment rate announced by the United States has increased in individual periods, investors will continue to increase their holdings of US dollars for the purpose of maintaining value, thus pushing the US dollar index to climb continuously.