Testing the Overreaction Hypothesis on the BIST30 Index and Dow Jones: The Case of the 2008 Financial Crisis Process

Introduction –Emerging markets are under the influence of many external factors in global market conditions. International interest rates and price fluctuations in major stock market indices are also among these factors. The FED policies shape the international capital movements in particular, which significantly affects the emerging markets. For this reason, emerging stock markets may show different reactions especially in times of crisis. Purpose –The purpose of this study is to investigate whether the BIST30 index acted in accordance with the overreaction hypothesis (ORH) against the return changes in the Dow Jones Industrial Average (DJIA) index in the process of the 2008 global financial crisis. Methodology –The data set of the study was analysed by dividing it into two periods. The first period is the monetary expansion period between 17 August 2007, when the Federal Reserve (FED) reduced the interest rate for the first time, until 22 May 2013 when the FED announced that it would reduce the bond purchases. The second period is the monetary contraction period including the dates between 23 May 2013 and 1 June 2017. An error correction model (ECM) was established in both periods for the indices, determined as cointegrated. The validity of the ORH was tested by Cumulative Abnormal Return (CAR) Analysis. Findings– According to the ECM, the authors identified that the effect of short-term changes in the DJIA return in the monetary expansion period on BIST30 index return was higher than that in the monetary contraction period. However, according to the findings obtained from the CAR analysis results, the BIST30 index did not generally act in accordance with the ORH against the DJIA. Findings can be appreciated as a decision-making tool especially for investment specialists and investors interested in securities investments.