The optimal capital structure is that structure which ? – Business & FinanceReport
Under different theory, things differ a lot. Perhaps there’s no optimal capital structure in pecking-order theory but in reality most companies set a target debt-to-equity (D/E) ratio. Anyway, let’s focus on trade-off theory first.
Trade-off theory argues that there’s an optimal amount of debt of each firm. At this level of debt, firms can take the most advantage of debts. Debts can be tax shield so that they can save money for firms to reinvest in other projects so as to earn more profits. However, debts can be quite dangerous because highly leveraged firms may face bankruptcy and financial distress costs (no matter they’re direct or indirect) may increase the cost of debt of the company. Therefore, there must be a level of debt that make the benefits of debt and potential danger of debt offset each other. In another word, the marginal revenue of debt equals the marginal cost of debt. But remember, the real cases are not as easy as we put here.
You can learn more on your corporate finance class and good luck to you!