Why weighted cost of capital is said to be a you shaped?

The weighted average cost of capital (WACC) is often depicted as a U-shaped curve because it reflects the relationship between a company's capital structure and its overall cost of capital. Initially, as a firm increases its debt levels, the WACC decreases due to the tax shield benefits of debt financing and the lower cost of debt compared to equity. However, beyond a certain point, excessive debt leads to increased financial risk, raising the cost of both debt and equity, thereby causing the WACC to rise again. This results in the U-shape, illustrating the optimal capital structure where WACC is minimized.