Private investors aim to invest their available capital as profitably as possible. They either follow their own investment strategies or, more commonly, strategies from specialized literature or financial advisors. Due to the introduction of the flat tax as part of the corporate tax reform in 2008, existing strategies should be reconsidered. The taxation of income from capital assets through the flat tax will lead to changed returns on various investment products in the capital market. To optimally adjust investment strategies to the flat tax, it is essential for the investor to understand the principles of capital asset taxation. This study aims to help private investors grasp this complex topic and develop tax-optimized investment strategies.