The work deals with the accounting of financial instruments in trading portfolios. It begins with a brief overview of the BilMoG (German Accounting Law Modernization Act) before introducing individual financial instruments. The focus of the discussion is on the so-called Asset Backed Securities. Furthermore, the previous accounting regulations are compared with the current regulations for credit and financial services institutions, in order to provide an overview of the associated opportunities and risks resulting from the modernization of German accounting law. Additionally, the most important valuation methods, such as the Black-Scholes model, are presented.