... Vietnam' s stock market is still new, hasn't had rules of the market, the calculation of the general index of the market still difficult The beta coefficient calculation must rely heavily on the estimates, ... wonder the stock price in the choice of data of, which led to difficulties for the analysis and valuation share The third difficulty is the operation of the credit assessment institution in Vietnam ... the stock market on emotions, investors follow herding behavior rather than analysis, stock valuation to get the investment decisions for themselves Vietnam' s stock market have gone through the...