This study was conducted to determine the relationships between financial assets and the differences between these relationships in the pre- and post-COVID-19 periods. The study aims to reveal whether the movements of financial assets have changed during the pandemic. In the study, date ranges were determined separately for the period before and after COVID-19. The dates March 09, 2016–March 09, 2020 were determined as the pre-COVID-19 period, and the dates March 09, 2020–March 09, 2024 were determined as the post-COVID-19 period. The study obtained daily logarithmic returns of BIST 100, euro, and gold assets, and applied Correlation Analysis and Granger Causality Test. As a result of the study, the correlation levels of the variables and causality relationships are reported in the pre- and post-COVID-19 periods. When the findings obtained were evaluated, as a result of the correlation analysis, it was determined that the correlation levels decreased in the post-Covid period. In terms of causality relations, it was observed that the relationship levels increased in the post-COVID-19 period. In addition, it is another result that there are differentiations in the relevant periods. When the findings are evaluated together, determining the causality relationship between the substitution power of assets and returns is important for portfolio construction, asset investment, and risk-taking levels. The study is intended to guide individual investors, decision-makers, and the industry.
Cite this article as: Medetoğlu, B., & Saldanlı, A. (2025). Causality relationship between BIST 100 index, euro and gold returns during the COVID-19 pandemic. Journal of Business Administration and Social Studies, 9, 0012, 1-11.