Return on investment (ROI) is an important indicator of the success of an investment, which can help investors understand the value of the investment project. In this article, we'll take a closer look at how to calculate the return on investment after investing in a stake and explore how to maximize shareholder benefits.

1. The method of calculating the return on investment

ROI is the ratio of investment income to investment cost and can be calculated by the following formula:

Return on Investment (ROI) = (Return on Investment - Cost of Investment) / Cost of Investment

例如，某投資者購買了一家公司的股票，投資成本為10萬元，一年後該公司盈利，投資者的收益為5萬元。那麼投資回報率為：

ROI = (50 - 0) / 0 = -0.0 = -0%

In this example, the investor's return is -50%, indicating that the investment was not successful.

2. Evaluate the profitability of the investment project

Before investing, it is crucial to understand the profitability of the investment project. It can be assessed by:

1. Analyze the company's financial statements: By studying the company's financial statements, you can understand the company's assets and liabilities, profitability and cash flow.

2. Understand the current situation of the industry: Familiar with the market environment, competitive landscape and development trend of the industry in which the investment project is located will help to evaluate the profitability potential of the project.

3. Predict future earnings: Predict the company's future profitability based on historical data and market trends.

3. How to maximize the interests of shareholders

The ultimate goal of investors is to maximize the return on their investment. Here are some suggestions:

1. Regularly review your portfolio: Review your portfolio regularly to eliminate underperforming investments and optimize your portfolio.

2. Diversify investment risk: Diversify investment risk by investing in companies in different industries and different market capitalizations.

3. Long-term investment: Long-term investment can help avoid short-term market fluctuations and achieve stable growth in investment returns.

4. Maintain attention to corporate governance: Pay attention to the company's management and governance structure, keep abreast of the company's strategy and operation, and provide strong support for investment decisions.

5. Seek professional advice: Consult a professional investment advisor to obtain professional advice on investment and improve the accuracy of investment decisions.

With the above methods, investors can better calculate the return on investment and maximize shareholder benefits.