Asimetrik Stokastik Volatilite Modelinin BIST100 Endeksine Uygulanması

Öz

Bu çalışmada asimetrik stokastik volatilite ASV modeli lognormal dağılım varsayımları altında 2007-2008 küresel finans krizi dikkate alınarak BIST100 endeksine uygulanmıştır. ASV modelinin parametrelerinin tahmininde Bayesyen yaklaşımına dayalı MCMC Markov Chain Monte Carlo, MCMC algoritmasından yararlanılmıştır. Çalışma bulguları BIST100 endeksi için asimetrik tepkinin ve yüksek volatilite kalıcılığının söz konusu olduğuna işaret etmektedir. 2007-2008 küresel finans krizinin daha çok asimetri parametresi üzerinde etkili olduğu bu nedenle küresel finans krizi döneminde BIST100 endeksi getirisindeki değişimlerin BIST100 endeksi volatilitesi üzerinde daha fazla etkili olduğu anlaşılmaktadır. Çalışma bulgularının BIST100 endeksinin volatilite dinamiklerinin daha iyi anlaşılabilmesi ve ASV modellerinin Türk finans piyasalarına uygulanabilirliği açısından önemli olduğu düşünülmektedir.

Anahtar Kelimeler

• Asimetrik stokastik volatilite modeli, BIST100 endeksi, Bayesyen yaklaşımı.

An Empirical Application of an Asymmetric Stochastic Volatility Model to ISE100 Index

Öz

This study applies an asymmetric stochastic volatility ASV model to the ISE100 index by considering the 2007–2008 global financial crisis under the assumption of a lognormal distribution. The MCMC Markov Chain Monte Carlo algorithm based on a Bayesian approach is used to estimate the parameters of the ASV model. According to the results, the return volatility of the ISE100 index exhibits volatility persistence and leverage effect. Additionally, the model indicates that the global financial crisis of 2007–2008 mostly affects the leverage-effect parameter, implying that changes in the return of the ISE100 index more greatly influenced its volatility during the crisis. The findings contribute to the understanding of the volatility dynamics of the ISE100 index and the applicability of ASV models to Turkish financial markets.

Anahtar Kelimeler

• Asymmetric stochastic volatility model, ISE100 index, Bayesian approach.

Kaynakça

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