Before revision:  Portfolios are constructed by binning the securities according to their risk values. The mean risk value and the mean return in excess of market returns for each bin is calculated to get the risk-return patterns of the portfolios. The investigations have been carried out for both long (~18 years) and shorter  (~9 years) terms that include the dot-com bubble and the 2008 crash periods .
After revision:  Tests carried out for both long (~18 years) and shorter (~9 years) terms that include the dot-com bubble and the 2008 crash periods .