
From the graph above also we can know that, debt or leverage increases in the profitability of the firm and make this company has a better capital structure and this company gets its optimal capital structure at the D/E ratio is 180, 17% and the stock price Rp.800, it means that at this level company still get the benefit of debt because after this level if company still do debt, there will be two effects, first, it just caused the firm value of company would decrease because the increasing of the profit benefit from using debt will not proportional with the increases in financial distress and agency problem cost. Second, after the optimal capital structure point, the rising costs of the likelihood of firm financial distress and agency cost cause the market value of the levered firm to decline, that’s why the pricing cost of this company get decrease after optimal capital structure.
3. Working Capital Management of The Company

After make the calculation of working capital in this figure below, showed that there is no negative result. This is meaning that the firm never experienced a deficit in working capital during period 2004-2008. Why did the firm should maintain their working capital in a positive value? The firm should maintain their working capital in a positive value to ensure that the firm is able to continue its operations and that it has sufficient funds to satisfy both maturing short-term debt and upcoming operational expenses.

In this company, the cash conversion cycle calculation demonstrates that in 2008 is their best performer in managing its cash flow in this supply chain (32 days) while 2004 is the worst CCC performs (191 days). All of these cash to cash cycles demonstrate ineffective cash management because from 2004 until 2008 this came from its lower payable turnover than its receivable and inventory which caused a positive CCC. Like the earlier theory, the lower number of CCC is the more efficient company. Therefore, improvement must also focus on how to manage their inventory more effectively.
4. Conclusion
From the graph, it can be seen that D/E Ratio and closing price has the same pattern. That pattern is when D/E Ratio increased then closing prices also increased and when D/E Ratio decreased then closing price decreased too. It happened because if company used debt then it can be seen as positive signal that the company has ability to pay the interest in the future. While company is issuing stock, it can be seen as negative signal that the firm’s managers feel the company’s stock is overvalued (i.e. earnings are likely to decline in the future) and they wish to take advantage of a market opportunity. Furthermore, the graph used Trade-off Theory for analysis because the debt to equity ratio changed significantly in each period and company used debt for financing its activity.
From the analysis above can be concluded that this company has a good performance of working capital because this company never experienced a negative value of working capital. This company always has enough assets to continue its operations and that it has sufficient cash flow to satisfy both maturing short-term debt and upcoming operational expenses.
While from the cash conversion cycle this company is experienced ineffective condition because the number of the cash conversion cycle is quite high. This high number show that this company will be able to repay the cash but with long time. A good company should be experienced in low cash conversion cycle.