From the beginning of 2020, the whole world has been shaken by a contagious disease called Covid-19, its actual name being SARS-CoV-2. It first appeared in China, in Wuhan, Hubei Province, in December 2019, and the World Health Organization (WHO) was informed about it on the 31st of December...

This paper aims to discuss market efficiency due to the changes that appeared in this field after the COVID-19 outburst. The OMX exchange and its indices are taken into consideration because they represent markets not analysed in such a context before (a) Baltic: Estonia, Latvia and Lithuania;...

This paper analyzes market efficiency (EMH) with the day-of-the-week effect and the changes that might appear after the outbreak of the COVID-19 pandemic, based on the example of the OMX Exchange and its indices. Before the pandemic, only the OMX Baltic All‑share index was efficient; during...