Analysis of transaction-based manipulation cases in the Istanbul Stock Exchange equity market during the Coronavirus pandemic

The aim of the study is to investigate whether the transaction-based manipulation events that took place during the coronavirus pandemic have an effect on the daily returns, trading volume changes and volatility of manipulated stocks in Istanbul Stock Exchange. In this period, a control group consisting of the stocks closest to the manipulative stocks in terms of paid-in capital and operating in the same or similar sector selected in order to compare with the manipulated stocks was formed. To analyze whether there is a significant difference between the two groups in manipulation, before manipulation and post-manipulation periods, regression analysis was carried out with dummy variables defined according to the manipulation status. The data analyzed in the study were taken from Investing.com, Thomson Reuters databases and the official website of the Capital Markets Board. The date range was determined as February 17, 2020 - March 17, 2021, and since the pre-manipulation period was also examined, the analyzes were started with a date earlier than the date when the first coronavirus case in Turkey was announced. As a result of the analyzes, it was found that the change in the trading volume during the manipulation period and the volatility in the post-manipulation period differed significantly in manipulative stocks compared to other stocks. As an outcome of transaction-based manipulation, there is an artificial increase in trading volume based on heavy trading in manipulated stocks.