From the beginning of 2018, the dollar index started to fall unexpectedly when the 10-year yield of the US dollar still held the yield of 10-year German bund above 200 basis points; the exchange rate of the US dollar against the euro breaks away from the previous situation and is showing the reverse trend. In response to this anomalous phenomenon, the European Central Bank discussed the "currency war" in its latest January meeting minutes. Europe worries about losing the currency cold war with the US.