Author(s)

Yingying Zhu, Ling Zhou

Corresponding Author

Yingying Zhu

ABSTRACT

Due to the immediacy and universality of the Internet, the exposure of the vaccine incident on July 15, 2018 pushed changchun changsheng listed company to the forefront. In this context, this paper uses the event study method to examine the impact of vaccine events on the stock prices of changchun changsheng listed company and its related listed companies. The study found that the vaccine incident did have an impact on the stock prices of changchun changsheng and non-incident companies in the same industry, but there were differences. On this basis, this paper further divides non-incident companies into vaccine companies and non-vaccine companies. By comparing the abnormal rate of return and the cumulative abnormal rate of return of the two companies, it shows that the changchun changsheng vaccine event also has a different impact on the stock prices of vaccine companies and non-vaccine companies. Based on the above empirical results, this paper puts forward some Suggestions on the measures to be taken by listed companies in the face of negative events.

KEYWORDS

Accine events; Event study; Abnormal rate of return; Cumulative abnormal rate of return