On July 31, the Bank of Japan unexpectedly raised interest rates, earlier than the consensus expectations in September and announced plans to cut bond purchases, the yen strengthened sharply, the dollar/yen fell below 150, and the Chinese yuan soared nearly 300 points during the day. Thereafter, the Federal Reserve will announce the interest rate resolution, the market is expected to September the probability of the first cut in about 90%, the expectation of interest rate cuts to promote U.S. bond yields downward, making the dollar index continued to oscillate. Some analysts said that the yen turned around and appreciated does not mean that the yuan will follow the rapid appreciation, before the U.S. election, such as the dollar index due to risk aversion, the yuan is also difficult to maverick, the Japanese economy is still weak, the yen's strength is difficult to sustain.