The economic security of any company depends on its solvency and financial stability. It is also affected by uneven economic development due to the global financial crises, the impact of the COVID-19 pandemic, increased competition from industrial and commercial companies, and military conflicts. Thus, it is necessary to assess the stability of companies as a basis for their economic security, taking into account the indicators of solvency and financial stability. The paper used systematization, comparative analysis, ranking, expert interview (in-depth interview), and Fishburne’s method. First, the scheme of ensuring the financial stability and solvency of production and trading companies is proposed. Second, the evaluation indicators system is developed, and the rating scale of stability of production and trading companies is determined. According to the results, evaluation indicators were formed; some were calculated according to companies’ financial statements and management accounting. Finally, to increase the efficiency of technical and economic parameters, areas for regulating the activities of companies and ensuring their stability were identified. According to an in-depth interview with experts, the sampled company received 69 points and corresponded to a sufficient level of stability. Factors that negatively affected the stability of companies’ activities include quality indicators, namely compliance with standards, company image, digitalization, compliance with corporate culture, and personnel management policy.