The aim of the research was to find out the opinions of stockbrokers working at the Warsaw Stock Exchange regarding the behaviour of Polish investors in the face of the coronavirus (COVID-19) pandemic. The research was carried out among 51 stockbrokers representing brokerage houses with a long history of operations. It has been found that psychological conditions of people and stock market sentiments play an important role in the decision-making process, and irrational investor behaviours, including largely herd effects, are particularly evident during the pandemic. The research shows that the occurrence of the coronavirus has not reduced the activity of Polish investors. Thus, significantly growing interest in shares of companies listed on the Warsaw Stock Exchange has been noted. The behaviour and attitude of market participants towards risk were volatile during the developing pandemic, which manifested itself in rapid buying of overvalued assets or rapid selling of assets.