An assessment of the variations in a fund's monthly returns in comparison to similar funds, with an emphasis on downward variation. The greater the variation, the larger the risk score. If two funds have the exact same return, the one with greater variations in its return is given the larger risk score. In each Morningstar Category, the 10% of funds with the lowest measured risk are described as Low Risk, the next 22.5% Below Average, the middle 35% Average, the next 22.5% Above Average, and the top 10% High. Morningstar Risk is measured for up to three time periods (three-, five-, and 10-years). These separate measures are then weighted and averaged to produce an overall measure for the fund. Funds with less than three years of performance history are not rated.