The Covid-19’s Impact on Stock Prices among Different Sectors - An Event Study Based on the Istanbul Stock Exchange Market

The Covid-19 pandemic has deeply affected our health and social life as well as the financial markets. Although the global economic effects of the coronavirus are not yet clear, it is observed that there is a reaction in the financial markets to the developments related to the pandemic. Studies show that the pandemic has strong impact on stock markets and increases uncertainty. The purpose of this study is to examine whether the stock prices of companies traded on the Istanbul Stock Exchange Market between 02.14.2019 and 04.01.2020 are affected by the Covid-19 pandemic. In this context, the stock prices of the six major sectors traded and thought to be affected in Istanbul Stock Exchange Market during the period examined were analyzed using the "event study" method of the effects of Corona virus. In the analysis, the event window was taken as (- 15, + 15) trading days. The effects of the Corona virus in the relevant period were examined separately for each company in the selected sectors, and after calculating the abnormal returns, the effect on the average abnormal returns and cumulative abnormal returns were analyzed. According to the research results; when the general picture of selected sectors in Covid-19 is examined, statistically significant negative average cumulative abnormal returns are obtained. According to these results, Istanbul Stock Exchange has affected by Covid-19 pandemic during the period under examination.

RISK-RETURN PERFORMANCES OF REAL ESTATE INVESTMENT FUNDS IN TURKEY INCLUDING THE COVID-19 PERIOD

The purpose of this research is to give an insight into the Turkish real estate investment funds (T-REIFs) by comparing their risk-return performances with the main benchmark investment tool Istanbul Stock Exchange-100 (BIST-100) Index. This study evaluated the performance of T-REIFs in four different periods between January 2017 and December 2020 (2017m1–2017m12, 2018m1–2018m12, 2019m1–2019m12 and 2020m1–2020m12) including the Coronavirus Disease (Covid-19) period by applying the Sharpe and Treynor ratios. In a well-diversified portfolio both ratios give the same results, but in the presence of non-systematic risk and the portfolio is poorly diversified, the Treynor ratio is a better indicator than the Sharpe ratio. The findings of this study show that rankings of Sharpe and Treynor ratios may differ for each period. These results also support the fact that the portfolios of funds in the Turkish real estate market are not well diversified. By providing corporate tax exemptions, and by enabling the investors to diversify their investments and reduce their risks, real estate investment funds are important alternatives to direct real estate investments in Turkey. In that context, being one of the pioneer studies in this niche and a new topic in emerging markets, analyzing the return performances of T-REIFs and comparing them with the returns of the BIST-100 index is aimed to contribute to literature as well as provide insight to investors who may consider investing in the Turkish real estate capital market instruments.

Financial Performance Analysis of Companies Registered on BIST Corporate Governance Index

The aim of this study is to measure the 2018 financial performance of 49 businesses that are registered in the Istanbul Stock Exchange Corporate Governance Index. Therefore, the financial performances of 49 businesses were compared to the ROA, ROE, ROS, and MV performance indicators that were determined for the measurement of financial performance. For comparison, first, the significance levels of the indicators were determined by the AHP method, and MV was determined to be the most important indicator. The PROMETHEE method was used to be able to financially compare the businesses, and Tüpraş Türkiye Petrol Rafinerileri A.Ş. (Tüpraş Turkey Petroleum Refineries Inc.) was the most successful corporate governance business within the specified time period. The least successful business is Pınar Su ve İçecek Sanayi ve Ticaret A.Ş. (Pınar Water and Drink Industry and Trade Inc).

Stock Dividend Ex-Day Abnormal Return

This study examines the impact of the ex-day of stock dividend on stock return and volume on Borsa Istanbul stock exchange. The data covers 1,220 stock dividends associated with 305 companies over the period 1997-2018. A positive abnormal return and volume is seen around the ex-day of stock dividend. The cumulative average excess return over market return starts to significantly rise ten days before ex-day and reaches its highest level on the ex-day before falling back in the days following. Our findings show that abnormal return around ex-day is strongly associated with stock dividend pay-out ratio, asset size and a company’s market value. The share of listed companies with higher stock dividend pay-out ratio or lower asset size or lower market capitalization, can generate respectively 5.97%, 6.08% and 5.88% abnormal return over market index return.

Stock Pattern Classification from Charts using Deep Learning Algorithms

Pattern classification is related with the automatic finding of regularities in dataset through the utilization of various learning techniques. Thus, the classification of the objects into a set of categories or classes is provided. This study is undertaken to evaluate deep learning methodologies to the classification of stock patterns. In order to classify patterns that are obtained from stock charts, convolutional neural networks (CNNs), recurrent neural networks (RNNs), and long-short term memory networks (LSTMs) are employed. To demonstrate the efficiency of proposed model in categorizing patterns, hand-crafted image dataset is constructed from stock charts in Istanbul Stock Exchange and NASDAQ Stock Exchange. Experimental results show that the usage of convolutional neural networks exhibits superior classification success in recognizing patterns compared to the other deep learning methodologies.

The Effect of Systematic Risk and Previous Period Returns on Portfolio Selection

There are many techniques to determine investable set of portfolios given return data of assets. However, the theoretical results do not always point out the best portfolios in practice. This is due to the fact that financial dynamics are so difficult to be modelled and this requires many assumptions. The investor may have some preferences to select portfolios. In this study, two selection criteria are proposed to be applied in a mean variance optimization. These criteria are beta coefficient which is a measure of systematic risk and previous period return.The study has an empirical analysis applied on Istanbul Stock Exchange. The findings of the study confirm that these selection criteria may be used to obtain investable portfolios. The analysis with beta selection criteria reveal that the portfolio with lowest 5 beta coefficients is the best alternative. This means that the advantage of low beta which is a natural hedge when stock values declineis superior to diversification benefits of adding new stocks.The previous period return analysis suggest two alternative portfolios. In addition, one of these portfolios generate higher return than the portfolio selected with beta selection criterion. This is also a higher risk portfolio. Therefore the decision is based on risk profile of the investor.This research offer to add selection criteria to the standard approach which is beneficial for academic and practical purposes in portfolio management.