Efficiency of banking sector stock market: structural break and long memory

Bu çalışmada 2001 kriz sonrası dönem olan 2003-2007 yılları arasında Türk bankacılık sektörünün zayıf formda etkinliği yapısal kırılma testleri ve güçlü hafıza modelleri ile araştırılmıştır. Yapısal kırılmayı göz önünde bulundurmadan elde edilen sonuçlar bankacılık sektöründe zayıf formda etkinliğin varlığına işaret etmektedir. Bunun yanı sıra, hisse fiyat serilerinin tümünde yapısal kırılma tespit edilmiş ve kırılmanın etkisi ortadan kaldırıldığında fiyat serilerinin güçlü hafıza özelliği gösterdiği ve uzun dönemde ortalamasına geri döndüğü tespit edilmiştir. Bu sonuç bankacılık sektörünün zayıf formda etkin olmadığını göstermektedir.This study provides empirical evidence on weak form efficiency of the stock market in the banking sector after 2001 economic crisis in Turkey over a period of 1990-2007. It has been investigated with structural break test and long memory models. The results obtained ignoring the structural breaks point out that there exist a weak form efficiency in the stock market. Besides, it has been determined structural break effect in all stock prices series. It has been concluded that the stock prices series is mean reverting long memory process after removing the structural break effect. This result indicates that banking sector is not weak form efficient

Volatility Spillover Effect from Volatility Implied Index to Emerging Markets

This study has investigated the effect of VIX, created as an implied volatility in the US, on 15 emerging stock markets with the application of GJR-GARCH model. According to the results obtained, the emerging stock markets have leverage effect in conditional variance and emerging bad news concludes that volatility further increases. The results of the analysis show that implied volatility index affect Argentina, Brazil, Mexico, Chili, Peru, Hungary, Poland, Turkey, Malaysia, Thailand and Indonesia stock markets through volatility increasesImplied Volatility, Spillover Effect, GJR-GARCH Model,Emerging Markets

Investor sentiments and stock markets during the COVID-19 pandemic

This study examines the relationship between positive and negative investor sentiments and stock market returns and volatility in Group of 20 countries using various methods, including panel regression with fixed effects, panel quantile regressions, a panel vector autoregression (PVAR) model, and country-specific regressions. We proxy for negative and positive investor sentiments using the Google Search Volume Index for terms related to the coronavirus disease (COVID-19) and COVID-19 vaccine, respectively. Using weekly data from March 2020 to May 2021, we document significant relationships between positive and negative investor sentiments and stock market returns and volatility. Specifically, an increase in positive investor sentiment leads to an increase in stock returns while negative investor sentiment decreases stock returns at lower quantiles. The effect of investor sentiment on volatility is consistent across the distribution: negative sentiment increases volatility, whereas positive sentiment reduces volatility. These results are robust as they are corroborated by Granger causality tests and a PVAR model. The findings may have portfolio implications as they indicate that proxies for positive and negative investor sentiments seem to be good predictors of stock returns and volatility during the pandemic

Cointegration Relations between Turkish and International Equity Markets and Portfolio Choices

In this study monthly equity index values of twenty two emerging and twelve developed markets are used for the determination of cointegration relations developed by Johansen. The results of cointegration analysis show that Turkish stock market is cointegrated with seven developed and five emerging markets. After determining the integrated equity markets, different international portfolio scenarios are created by using Markowitz mean-variance model. These findings suggest that Turkish portfolio managers are able to monitor their asset allocations and minimize risks if they obtain a better understanding of how emerging and developed equity markets are integratedCointegration, Emerging Markets, Developed Markets, Portfolio, ISE.

THE CAUSALITY RELATIONSHIP IN RISK BETWEEN FOREIGN EXCHANGE AND STOCK EXCHANGE MARKET

Finansal teori pay senedi piyasası ile döviz kurları arasında iki yönlü ilişki olabileceğini öne sürmektedir. Bu bağlamda ticaret dengesi modeline göre döviz kurlarının pay piyasasını etkilediği kabul edilirken, portföy dengesi modeli pay piyasasından döviz kurlarına yönelik bir nedensellik ilişkisi olduğunu belirtmektedir. Pay senedi endeksi ve döviz kurları iki önemli finansal enstrüman olduğundan dolayı, bu iki piyasa arasındaki dinamik ilişkinin araştırılması literatürde oldukça ilgi görmektedir. Bu çalışmada 2003-2016 yılları arasında BİST100 endeks getirisi ile Dolar ve Euro getirileri arasındaki nedensellik ilişkisinin varlığı araştırılmıştır. Literatürde yer alan çalışmalardan farklı olarak, Hong vd. (2009) tarafından geliştirilen aşağı yönlü nedensellik testi kullanılmıştır. Bu amaçla ilk olarak her bir getiri serisi için Riske Maruz Değerler (RMD) GARCH model ile tahmin edilmiş ve gerçekleşen kayıpların RMD'yi aştığı durumlar aşırı risk dönemleri olarak belirlenmiştir. Analiz sonuçları, risk durumunda döviz kurlarından pay piyasasına yönelik nedensellik ilişkisinin olduğunu belirtmektedirFinancial theory suggests that there may be bidirectional relationship between stock exchange and foreign exchange markets. In this context, while foreign exchange rates affect stock exchange market according to trade balanced model, portfolio balanced model indicates the presence of causal link running from stock exchange market to foreign exchange rates. Since stock exchange index and foreign exchange rates are two important financial instruments, the dynamic relationship between the two markets has been widely examined in the literature. In this study, the presence of causal link among stock returns series of BIST 100, US Dollar and Euro for the periods 2003-2016. Differently from existing literature, we employed downside causality test suggested by Hong et al. (2009). For this aim, we first estimate Value at Risk (VaR) for each returns series by using GARCH model and extreme risk periods are defined as actual loss exceeds VaR. Empirical results suggest the existence of causal link in risk running from foreign exchange to stock exchange market

Volatility spillover effects between Islamic stock markets and exchange rates: Evidence from three emerging countries

Empirical findings focusing on the relationship between capital markets and macroeconomic variables are used as data sources in determining policies for the development of the conventional and Islamic financial system. The aim of this study is to investigate the existence of volatility spillover effects between foreign exchange markets and Islamic stock markets in three major emerging countries, namely India, Malaysia, and Turkey using daily data for the period 2013-2019. Volatility spillover effects are investigated using the causality-in-variance test developed by Hafner and Herwartz (2006). In order to examine the nature of the relationship between the variables, and whether it changes over time, the time-varying test statistic is estimated using rolling samples. We find evidence in favor of volatility spillovers from the Islamic stock market to the foreign exchange market only in Turkey. The time-varying test results show that the presence of volatility spillover is at least one direction between exchange rates and the Islamic stock market at specific periods. Copyright (C) 2020, Borsa Istanbul Anonim Sirketi. Production and hosting by Elsevier B.V

Testing Adaptive Market Hypothesis in Global Islamic Stock Markets: Evidence From Markov-Switching Adf Test

Although market efficiency has been extensively examined in the literature, the studies generally focus on conventional stock markets. Since market efficiency is related to a well-functioning market, it is of great importance for the efficient allocation of resources and also providing sustainable economic growth. Market efficiency is not only important for conventional stock markets but also for the Islamic stock market as the Islamic stock markets are gaining prominence. An increase in the scope of Islamic markets worldwide creates the motivation for investigating the efficiency of Islamic stock markets. Hence there is a growing interest in Islamic stock markets. With a limited number of studies that analyze the efficient market hypothesis in Islamic stock markets, this paper aims to examine market efficiency in the global Islamic stock markets via Markov-Switching Augmented Dickey-Fuller (MS-ADF) test. The linear unit root test result shows that the global Islamic stock market indices exhibit random walk properties that are consistent with the Efficient Market Hypothesis. On the other hand, nonlinear test results suggest global Islamic stock markets exhibit two-state regime-switching characteristics. The MS-ADF test results indicate that the world and developed Islamic stock markets are stationary only in the high volatility regime and this finding supports the Adaptive Market Hypothesis. However, the emerging Islamic stock market is found to be stationary in both regimes that are contradictory for weak-form efficiency

Oil Prices and Global Stock Markets: A Time-Varying Causality-In-Mean and Causality-in-Variance Analysis

This study examines the Granger-causal relationships between oil price movements and global stock returns by using time-varying Granger-causality tests in mean and in variance. We use the daily returns from Morgan Stanley Capital International (MSCI) G7 and the MSCI Emerging Stock Market Indexes to distinguish between the effects of daily oil price movements on G7 countries' and emerging market countries' stock markets. We further divide the emerging markets into two groups as oil-exporting and oil-importing countries. For the oil market, we use both the West Texas Intermediate (WTI) and Brent oil daily price movements. While the Granger-causality-in-mean tests indicate a causal link from WTI oil prices and G7 countries' stock returns to MSCI emerging countries' stock returns, the Granger-causality-in-variance tests suggest no causal link from global oil market prices to stock market returns. Nonetheless, a causal link from the G7 countries' stock returns to the MSCI emerging countries' stock returns is detected. In addition, G7 countries' stock market volatility is found to Granger-cause Brent oil price volatility. The time-varying Granger-causality-in-mean and Granger-causality-in-variance tests present new and further insights. A causal relationship between oil price changes and G7 countries' stock returns is found for some periods during and after the global financial crisis. Time-varying Granger-causality-in-variance test results indicate evidence of causal linkages among oil prices and global stock market returns that are specific only to certain time periods. We also find that there might be a difference between the movements in Brent and WTI oil prices with respect to their Granger-causal effects on oil-importing emerging markets' stock returnsespecially after the global financial crisis. Our results provide further evidence that the effects of oil price movements on stock returns might be different depending on the volatility in the stock markets

Bitcoin ile Önemli Döviz Kurları Arasında Nedensellik İlişkisi

Bu çalışmanın amacı, Bitcoin ile Euro/Dolar, İngiliz Sterlini/Dolar, Kanada Doları/Dolar, Japon Yeni/Dolar ve Çin Yuanı/Dolar gibi önemli döviz kurları arasındaki dinamik ilişkiyi incelemektir. Bu bağlamda, Bitcoin ve döviz kurları arasında ortalamada ve volatilitede yayılım etkisinin varlığını incelemek için Hong (2001) tarafından önerilen ortalamada ve varyansta nedensellik testi kullanılmıştır. Ayrıca, Bitcoin ve döviz kurları arasındaki kuyruk bağımlılığının varlığını araştırmak için Hong vd. (2009) tarafından önerilen risk durumlarında nedensellik testi kullanılmıştır. 19 Ağustos 2011 ile 6 Ağustos 2021 tarihleri arasında günlük verileri kullanarak, Euro, Pound ve Kanada Dolar’ından Bitcoin’e yönelik tek yönlü ortalamada nedensellik ilişkisi tespit edilmiştir. Öte yandan, varyansta nedensellik testi sonuçları, Bitcoin ile Euro ve Pound arasında çift yönlü bir oynaklık yayılım etkisinin olduğunu göstermektedir. Ayrıca, Yuan ve Kanada Dolar'ın Bitcoin'in varyansta Granger nedeni olduğu belirlenmiştir. Risk durumlarındaki nedensellik testi sonuçları, Euro ve Pound’dan Bitcoin’e yönelik nedensellik ilişkisine dair kanıt sunmaktadır. Bununla birlikte Bitcoin’deki beklenmedik kayıplar, Yen’deki beklenmedik kayıpların Granger nedenidir. Genel olarak, ampirik sonuçlar Çin para biriminin Bitcoin ile daha az entegre olduğunu göstermektedir

The Effects of the COVID-19 Pandemic on Conventional and Islamic Stock Markets in Turkey

In order to reveal the macroeconomic effects of the Covid-19 pandemic, financial markets should also be handled in addition to the real sector. Investigating the changes in the stock market may give clues to analyze the effects of the pandemic on financial markets. The researches in question can be carried out for a country group or a single country. Studies that are conducted for a single country allow researchers to analyze problems more precisely and put forward more specific and convenient policy suggestions. Furthermore, while investigating the effect of the pandemic on stock markets, handling conventional and Islamic stock markets together can provide more comparative and realistic data in determining the policies regarding financial markets. The aim of the study is to examine the reaction of conventional and Islamic stock markets to the Covid-19 outbreak in Turkey. In the study, the DCC-GARCH method was applied by using the daily data from Feb 10, 2011 to Sep 02, 2020. The empirical results indicated that Islamic stock markets are more stable to the global Covid-19 outbreak shock than the conventional stock market in Turkey. Based on these findings it can be suggested that Turkey should take steps to support the development of the Islamic financial system to have a sounder financial system