You must be clear about essential points to carry out due diligence on stock, such as: 1. Check if the company's balance is clean, that is, know where the profits come from, what debts it has, the cash flows, etc; 2. Investigate if the company can maintain its competitive position in the area it operates; 3. Analyze which loans are off the company's balance sheet; 4. Know what the government standards are and if there are conflicts of interest; 5. Investigate ROE and its growth; 6. Fit long-term financial goals.