Mathias Külpmann presents a framework to evaluate whether the stock market is in line with underlying fundamentals. The new and revised edition offers an up to date introduction to the controversy between rational asset pricing and behavioural finance. Empirical evidence of stock market overreaction are investigated within the paradigms of rational asset pricing and behavioural finance. Although this monograph will not promise the reader to become a millionaire, it offers a road to obtain a deeper understanding of the forces which drive stock returns. It should be of interest to anyone interested in what drives performance in the stock market.