Internal learners in capital markets a research on the existence of trading: An application in Borsa Istanbul

There is no consensus in the literature on whether insider trading is a commercial offence that is tried to be controlled by legal regulations and laws around the world. It is explained as a way for real and legal persons to gain profit by accessing and using non-public information in the capital markets by using certain privileges and avoiding unfair gain or loss. In addition to the view that insider trading disrupts transparency and reliability in the markets and causes investors to move away from the market, the view that it is necessary for market balance is also dominant. In the first part of the study, information about the concept of insider trading, its elements, theories and legal regulations are given. In the second part, the case study method, which is the application subject of the study, is mentioned. In the last and third part of the study, in order to determine whether insider trading exists, the news flows of the companies in the BIST 100 index in 2021 and 2022 (a new business contract, mergers, acquisition of financial fixed assets, sale of financial fixed assets and sale of tangible fixed assets) are analysed. event days were determined by looking at. The event study method is based on the market model frequently used in the literature. In the last part of the study, the price movements of the companies in the BIST 100 index in 2021 and 2022 were analysed. As a result of the study, abnormal increases in the prices of stocks were observed in the period until the news day based on the first 10 and 5-day price movements before the relevant news day. The findings of the study, which investigated the suspicion of insider trading, support these suspicions.