CHANGING RISK-RETURN CORRESPONDENCE DURING THE COVID-19 TURMOIL: EVIDENCE FROM POLISH STOCK MARKET

Abstract

The article examines the impact of the shock induced by COVID-19 on the Polish stock market. As an object of research, 18 shares of companies included in the WIG20 index were taken. The impact of the shock is examined in the context of changing “risk-return”
correspondence. Three-time intervals were used for the study: before the shock, shock, in fact, aftershock. For the shock in fact period, two parameters have been introduced, which in pairs describe the “reaction” of stocks to a shock. These are shock deepness and recovery rate parameters. A linear type of regression relationship between them is identified. In the periods “before shock” and “aftershock”, “risk-return” correspondence is considered in terms of two approaches: variability and Value-at-Risk. Both approaches show an increased risk in the post-shock period but to varying degrees. The first approach shows an increase to a greater extent than the second. An explanation of this observation is given. The dynamics of changes in liquidity in terms of the average daily trading volume is considered complementary. The investigated dynamics shows an increase in trading volumes directly in the shock and post-shock periods. The explanation for this is considered in the aspect of reformatting by investors of their portfolios.