The ability of human mind in understanding and processing large amount of data is limited. Confronted with thousands of daily information, brain very often use heuristics and rely on less rational reasoning. Gender, age, genetic heritage, individual personality traits as well as other psychological factors are important determinants of investment decision, aside the economic ones. The way individuals react to different categories of news is also prone to be influenced by sentiments and feelings. This book surveys the literature in two different but inter-correlated directions: news asymmetric impact on stock returns and mood misattribution effect on investment decision and exemplify it for the case of the main European companies in healthcare industry. An alternative, further path to investigate the correlation between mood variables and investment decision is proposed in the final. The analysis should help shed some light in the way investment decisions are grounded and should be especially useful both for individual investors but also for investment companies, financial advisors and pension funds.