what is the beta of a market portfolio
Beta (finance) In finance, the beta (Î² or beta coefficient) of an investment indicates whether the investment is more or less volatile than the market as a whole. In general, a beta less than 1 indicates that the investment is less volatile than the market, while a beta more than 1 indicates that the investment is more volatile than the market. Volatility is measured as the fluctuation of the price around the mean: the standard deviation.