COVID-19 SALGINININ BORSA İSTANBUL PAY ENDEKSLERİNE ETKİSİ: SÜRÜ DAVRANIŞI ÜZERİNE BİR ARAŞTIRMA.

During the COVID-19 pandemic, effective worldwide, there have been many developments in not only the health field but also the economy and finance. This study tested herding behavior in price movements in Borsa Istanbul (BIST) during the COVID-19 period. For this purpose, the cross-sectional absolute deviation of returns (CSAD) methodology developed by Chang, Cheng, and Khorana (2000) allowed us to analyze the cross-sectional behavior of stock returns in the same index. Considering the results obtained for the three periods, namely the pre-COVID-19 period, the COVID-19 period, and the entire period, herding behavior detected in the BIST 30 Index during the entire period and the COVID-19 period. Again, during the pandemic, we observed that investors acted with herding behavior only in BIST Dividend 25 and BIST Sustainability indices. In addition, we revealed the existence of herding behavior in BIST stock indices in both rising and falling market conditions for the COVID-19 period. Accordingly, we observed herding behavior in the indices that include the shares of firms with a small market capitalization in upmarket conditions (BIST All Shares-100 and BIST SME Industrial) and in indices that include the shares of firms with a high market capitalization in down-market conditions (BIST 30 and BIST 50). [ABSTRACT FROM AUTHOR]