The acquisition, identification, and particularly the valuation of investments regularly lead to questions that pose special challenges for the creators and auditors of commercial annual financial statements. This also applies to the tax-related determination of profits. A systematic exploration of the topic of investment valuation as a whole is difficult based on individual essays for creators, consultants, and auditors, as the integration of the respective focal points into the overall context is lacking. This publication compiles and systematically addresses practical questions related to these important and multifaceted topics for the preparation and auditing of commercial annual financial statements. It also addresses the resulting tax-related questions. The presentation follows the lifecycle of an investment (from establishment to liquidation). The explanations are illustrated with examples and diagrams. The title in brief: - Investment Valuation - Commercial Annual Financial Statement - Tax-Related Profit Determination - Tax Balance Sheet.