“…e U.S. dollar, crude oil, and gold directly constitute the main part of the financial market, as well as the main place for policy authorities to implement financial control policies. After Wang [14] observed the effectiveness of the crude oil market by the local Hurst index through the rolling window of multifractal detrended fluctuation analysis, scholars successively compared the crude oil market with stocks [15,16], gold [17,18], foreign exchange [18,19], agricultural product futures [11,20], and other financial markets [21][22][23][24]. At the same time, Mali and Mukhopadhyay [25] used the multifractal detrended fluctuation analysis to study the correlation of the gold consumer price index and the gold market prices of the three major gold consuming countries in China, India, and Turkey and found that they all have multifractal characteristics.…”