IntroductionIn this article we will retest the theories and hypotheses of Penman, Richardson and Tuna using UK evidence, and try to determine whether data from a UK listed company United Kingdom can support their theories. Some of Piotroski's arguments will be discussed in this article, while the accounting system is also considered a crucial factor that can affect our test results. Methodology Correlations Basic Correlations The correlation table is a basic method to show whether the B/M effect is significant, and the relationships between different variables and future returns. To observe how the PRT model variables are associated with future returns, we divide the firm-year observations into 10 portfolios in each correlation table by book-to-market-year ratio, operational component of the B/M ratio (, financial leverage component of the B/M ratio (, and B/M minus the ratio of the operational component (. Returns are calculated as the return on the year of purchase and holding of the shares It covers the performance of the next 12 months which begins in the first month of the following financial year. For most companies release their annual reports in March or April, there is a time lag between future returns and market reaction. In our opinion, stock returns in the first four months are affected by expectations about company performance, which is why we use the following full year as future stock returns in this article. Since the stock return for the year 2010 is not available when we obtain the data, we exclude the data for the year 2009 in the correlation analysis since the dividend only occupies a small part of the yields. , the dividend yield is ignored in our correlation analysis to simplify our calculation. The negative data for the variables of B/M ratio, operational component and...... middle of article...... relationship analysis in Table 2. When NOA/P ≧1, the leverage effect is positive compared to the NOA/P; however, when NOA/P﹤1, leverage is negative relative to NOA/P. Regression V shows the leverage coefficient controlling for operational risk (corporate B/M ratio). For full sample testing, the coefficient is insignificant, meaning we cannot draw any reliable conclusions from this result. However, for NOA/P ≧1, the coefficient is significantly positive, and for NOA/P﹤1, the coefficient is significantly negative. If we divide the ND/P ratio into financial liabilities/P and financial assets/p as in regression VII, the coefficients FA/P are significantly positive in all three panels, but the FL/P is negative or insignificant compared to the returns future. This indicates that the high future return premium is given for high operational risk rather than financial risk..