Abstract: Under the environment of rising enthusiasm for promoting the upgrading of the industrial integration and mergers and acquisitions(M&A) of listed companies in China, domestic capital market starts a new round of M&A wave. At the same time, premium M&A level of listed companies in China shows a rapid upward trend, the significant uncertainty and high economic loss potential of high premium M&A may bring fall in stock price once they are perceived by the market. Whether high premium M&A would lead to the stock market overheating, and cause the occurrence of stock price crash risk, is the focus of attention of capital market. From the micro point of view, the article analyzes A share listed companies which have experienced M&A in 2008-2013, observes the impact of high premium M&A on stock price cash risk, and analyzes the internal mechanism from “agency conflict” and “managerial overconfidence”, finding that high premium M&A shows a significant positive correlation with future stock price crash risk. The main reason for the positive correlation between the two is the “managerial overconfidence” but not the “agency conflict” between shareholders and managers, and the analysis conclusion of “managerial overconfidence” is more explanatory.

Key words: high premium mergers and acquistions;stock price crash risk, agency conflict, managerial overconfidence