The past investigations have demonstrated that there is a connection between estimations of stock prices and the value changes brought about by public announcements. Along these lines the point of this paper is to inspect if the separate connection can be seen in stock market and how this connection is influenced by various classes and sorts of announcements. The exploration covers public announcements gave by organizations recorded in Vilnius Stock Exchange. Disentangled variant of occasion study system was utilized in this paper and normal outright and abnormal returns were processed. The vast majority of the outcomes in this paper are steady with the past investigations and a negative relationship between's the estimations of stock prices and the value changes brought about by public announcements was assessed.