Efficient Market Hypothesis is the base of modern finance theory. Many financial models are proposed based on EMH. With this formulation, many scholars have made empirical investigations on EMH, but a lot of researches conclude that the EMH is not satisfied with the reality. The finance markets are highly complex, irregular, so Fractal Market Hypothesis was proposed. EMH is a special of FMH, so it can be used to test the market's efficiency.There are a lot of problems in China's stock markets, so the China's stock market is not efficient. Some of the researches have confirmed this point. Based on these researches, this paper applies a new method called R/S analysis to test the efficiency of stock markets.This paper focuses on the comparative research on the fractal structure of stock markets by using R/S analysis. Firstly, Kolmogorov-Smirnov test method was used to test the normal distribution of indices, including DJI, S&P500, FTSE, N225, SSEC and SZCI, we find that the returns of these indices are not normal distribution. Then, the R/S analysis is utilized to research the efficiency of these stock markets. We find that the China's stock market has a more oblivious fractal structure, and drew a conclusion that China's stock markets are not efficient. Then we established a stochastic volatility estimation model with ITO process, and use the model to estimate the volatility of returns of China's stock markets. The methodology used to test the long-term memory of the volatility is Hurst's R/S analysis. The result shows that the returns' volatility has long-term memory and clustering.At last, this paper analyses the factors which affect the market efficiency, and proposes some advises. |