Beta　

Beta　贝塔　

measure of systematic or un-diversifiable risk of a stock.A beta coefficient of more than 1means that the company’s stock price has shown more volatility than the market index（e.g.，S&P 500）to which it is being related；usually，that indicates it is a risky security.If the beta is less than 1，it is less volatile than the market average.If it equals 1，its risk is the same as the market index.High variability in stock price may indicate greater business risk，instability in operations，and low quality of earnings.