This factor is designed to capture annual changes in corporate debt issuance activities. The logarithmic growth rate can effectively handle extreme debt changes while focusing on relative proportion changes rather than absolute changes. Empirical studies have found that over longer periods (such as 5 years), future returns on stocks of companies with high debt growth are generally lower, which is consistent with the comprehensive debt issuance effect. However, on shorter time scales (such as years or quarters), debt growth may reflect the company's active expansion and investment, and thus be associated with future positive returns. Therefore, the effectiveness of this factor is closely related to the time scale, and the choice of observation window needs to be considered when analyzing.