The Master Thesis at hand is concerned with the investment strategies of the stockmarket gurus Susan Levermann and Gerald Appel. This work investigates whetherthere is empirical evidence that the strategies of Susan Levermann, Gerald Appel, ora „naive“ portfolio selection can significantly outperform the benchmark. Theevaluation uses an empirical ex-post analysis of yields, volatilities, and Sharpe ratiosof ATX stocks that were selected by the criteria of the stock market gurus. Theanalysis spans the time 21.01.2002 31.12.2012 and includes three analyses ofperiods with “bullish”, “bearish”, and “sideway” market conditions. The result showsthat both strategies exhibit pros and cons over the benchmark during certain marketconditions. This is most clearly visible during weak market conditions. Under suchconditions, the strategies of Levermann and Appel can limit losses to 20 % and 40 %,respectively, whereas the benchmark and the “naïve portfolio” lose 60 % of theirvalue. However, the picture is different under “bullish” market conditions. There, thebenchmark as well as the “naïve portfolios” cannot be outperformed by the strategiesof the gurus. In the “sideway” phase, only the strategy of Gerald Appel achieves anexcess yield, but even his strategy cannot beat the “naïve portfolio”. Anothersignificant insight from this analysis is that the success of investment strategiesdepends crucially on the size of transaction costs.