Attempting to increase the efficiency of capital investments, investors are looking for other methods, in addition to the classic approach, enabling them to achieve extra profits or avoid losses. This seems to be complemented by theories based on the description of irrational investors' behavior and the non-economic aspects of the functioning of the capital markets. This study shows main theories of behavioral finance that show irrational inwestors' behavior e.i.: prospect, regret theory and anchoring. There is also description of spread between individualism and conformity of investors that very offen takes place on capital markets.