Petrol Fiyatlarındaki Belirsizlik, Jeopolitik Risk ve BİST GUBRF Arasındaki Etkileşim: Frekans Alanda Zamanla Değişen Bootstrap Nedensellik Testi

Yıl 2025, Sayı: 42, 114 - 128, 25.06.2025

Ömer Keskin

https://doi.org/10.26650/ekoist.2025.42.1607157

Öz

Risk ve belirsizlik, karar vericilerin ve hisse senedi yatırımcılarının karar verme süreçleri üzerinde etkiye sahip olan önemli faktörlerdir. Karar vericiler, ekonomik ve finansal sistemde yüksek risk ve belirsizlik durumunda uzun dönemli planlamalar yapmakta zorlanabilirler. Bu durum, kamu politikalarında ve özel sektör stratejilerinde ihtiyatlı bir yaklaşımın sergilenmesini zorunlu kılmaktadır. Diğer taraftan hisse senedi yatırımcıları ise yüksek risk ve belirsizlik dönemleri boyunca genellikle risk almaktan kaçınan bir tutum sergilemektedirler. Dolayısıyla yatırımcılar, portföylerini tahvil, altın, gümüş ve platin gibi daha güvenli varlıklara yönlendirmektedirler. Bu çalışma, frekans alanda zamanla değişen bootstrap nedensellik testini uygulayarak petrol fiyat belirsizliği endeksi (OPU), jeopolitik risk endeksi (GPR) ve Gübretaş’ın hisse senedi fiyatı (GUBRF) arasında nedensellik ilişkisi olup olmadığını belirlemeyi amaçlamaktadır. Ele alınan Nisan 1998-Temmuz 2024 dönemi için yapılan analizlerde petrol fiyat belirsizliği ve jeopolitik risk endekslerinin seçili hisse senedi fiyatı üzerinde kalıcı bir şekilde istikrarlı olmayan etkiler gösterdiği saptanmıştır. Bulgulara göre jeopolitik risk endeksinden GUBRF’e doğru uzun, petrol fiyatlarındaki belirsizlik endeksinden GUBRF’e doğru ise hem uzun hem kısa dönemli nedensel bağlantıların var olduğu tespit edilmiştir. Sonuç olarak, Gübretaş şirketinin yöneticilerine ve yatırımcılarına çeşitli küresel risk ve belirsizlik unsurları (özellikle enerji sektörünü doğrudan ilgilendiren gelişmeler) karşısında sürekli bir şekilde proaktif bir yaklaşımla hareket etme çabası içinde olmaya çalışmaları önerilmektedir.

JEL Classification : Q10 , Q13 , D81

Anahtar Kelimeler

Gübretaş , Petrol Fiyatlarındaki Belirsizlik , Jeopolitik Risk

Interaction between Uncertainty in Oil Prices, Geopolitical Risk, and BIST GUBRF: Time Varying Bootstrap Causality Test in the Frequency Domain

Öz

Risk and uncertainty are critical factors affecting the decision-making processes of policymakers and stock market investors. High levels of risk and uncertainty in economic and financial systems undermine the ability of policymakers to conduct effective long-run planning. This situation necessitates the adoption of prudent strategies in the formulation of public policies and the development of private-sector initiatives. Stock market investors often exhibit risk-averse behaviour during periods of high risk and uncertainty. Therefore, investors allocate their portfolios towards more secure assets such as bonds, gold, silver, and platinum. This study examines the causal relationship between the oil price uncertainty index (OPU), the geopolitical risk index (GPR), and the stock price of Gübretaş (GUBRF) by employing the time-varying bootstrap causality test in the frequency domain. Analyses conducted from April 1998 to July 2024 revealed that oil price uncertainty and geopolitical risk indices exhibited nonpermanently unstable effects on the selected stock price. The findings show a long-run causal connection between the geopolitical risk index and the GUBRF, and causal connections in both long- and short-run between the oil price uncertainty index and the GUBRF. Consequently, it is recommended that Gübretaş’s managers and investors adopt a continuously proactive approach in responding to various global risks and uncertainties (especially developments that directly concern the energy sector).

JEL Classification : Q10 , Q13 , D81

Anahtar Kelimeler

Gübretaş , Uncertainty in Oil Prices , Geopolitical Risk

Kaynakça

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