Özet:

The latest developments in the financial sector have shown that the effective market hypothesis remains insufficient in the explanation of the variables in the current market, and the recent developments in the behavioral finance field have played a major role in addressing these deficiencies. In this study, the excessive confidence, excessive optimism, excessive pessimism and rational expectations of behavioral errors were used to explain the volume of transactions in the Stock Exchange in Istanbul. The data set in the analysis is made up of daily values between the years 1995-2014; a total of 19 years. In the study, regression analysis has often taken advantage of the preferred small-quarters method, and it is achieved as a result of the study that changes in the trading volume of the Borsa Istanbul 100 Index are significantly affected by investors’ generally non-rational behavioral finance types.  Only rational expectations showed meaningless results, and the findings occurred that the rational hypothesis was rejected at the Stock Exchange in Istanbul. As a result, it is also achieved that the Stock Exchange of Istanbul is active in a weak form.