The work addresses four central questions related to IPOs: First, it examines whether and to what extent the underpricing phenomenon was present in the Neuer Markt between 1997 and 2003. Second, it empirically investigates whether a systematic negative long-term performance can be observed for the IPOs on the Neuer Markt. To this end, the performance of the IPO companies from the Neuer Markt is analyzed over a period of up to 24 months following the initial public offering. Third, based on the empirical results regarding underpricing and long-term performance, a statement is derived about the information efficiency of the Neuer Markt. In particular, it addresses the question of whether the primary market or the secondary market was information-efficient in the sense of Fama and Jensen. Finally, using econometric analysis methods, the theoretical explanations for the underpricing phenomenon are examined for their relevance to the underpricing on the Neuer Markt. This aims to answer the question of which explanatory models have the highest explanatory power for the underpricing phenomenon.