Öncü, Mehmet AkifÜnal, AslıhanDemirel, Oğuz2025-03-242025-03-2420172147-92082147-9194https://doi.org/10.17130/ijmeb.2017331332https://hdl.handle.net/20.500.12684/18494The aim of this study is to investigate the Day of the Week Effect DWE in Borsa Istanbul BIST-100 Index. For this purpose, a dataset of closing prices of the firms was gathered from January 03.2005 to November 06.2015. The data were transformed to return series bytaking logarithmic differences, and analyzed with GARCH 1,1 Model. According to the findings, although the coefficients representing the returns of Monday and Thursday are statistically significant, the returns of the trading days of the week are equal. Consequently, for the related period, DWE was not detected in BIST-100 IndexThe aim of this study is to investigate the Day of the Week Effect DWE in Borsa Istanbul BIST-100 Index. For this purpose, the dataset of closing prices of the firms was gathered from 03.01.2005 to 06.11.2015. The data transformed to return series by taking logarithmic differences, and analyzed with GARCH 1,1 Model. According to the findings, although the coefficients representing the returns of Monday and Thursday are statistically significant, the returns of the trading days of the week are equal. Consequently, for the related period, DWE did not detected in BIST-100 Index.tr10.17130/ijmeb.2017331332info:eu-repo/semantics/openAccessDay of the Week Effect|GARCH Model|BIST-100 Index|Haftanın Günü Anomalisi|GARCH Model|BIST-100 EndeksiArticle133521534