Even after the adoption of the MoPeG, there has so far been a lack of analysis of the civil law company (GbR) shareholder. This gap is filled by the thesis. In a first step, the thesis tries to define the real-typical GbR shareholder and points out the gaps that remain in such a definition. Subsequently, it develops two ideal-typical GbR shareholders using both the real-typical results found and the findings of behavioral economics. It shows why statutory law should be oriented towards a non-professional shareholder. On this basis, a critical analysis of the MoPeG follows in its various stages of development, from the Maurach Draft to the enacted law.