Q.2528 Global Asset Management (GAM) has a reputation for a robust risk management process. It is known for its clear expectations and risk profiles that are outlined for their various asset classes, which allows them to remain consistent with their investment philosophy. GAM utilizes a popular risk-monitoring tool that uses a well-defined risk forecasting model. As a part of their risk monitoring process, they regularly check if the portfolio's actual tracking error is consistent with the targeted tracking error outlined in their risk plan. Recently, during a routine check, they found that the forecasted tracking error of their US Equity Fund was deviating from the target by a significant amount. They discovered that this was due to an over-investment in value-themed assets by one of their portfolio managers, even though GAM primarily focuses on growth-themed assets. However, the portfolio manager argues that while the style of the portfolio might have drifted, the overall risk level remains within the risk budget and therefore should not be a cause for concern. He suggests that this "style drift" provides an opportunity for higher returns without violating the risk limit set by GAM's client. Based on the vignette, which of the following best describes why the portfolio manager's argument might not be completely accurate from the perspective of effective risk management?