The Efficient Market Theory and Mergers and Acquisitions （M＆As） Puzzle： Evidence From Italy

The efficient market theory is a central point in finance. If the capital market is competitive, the investors cannot expect superior gains from their investment strategies with respect to the risk profile. Event studies are an approach to verify the impact of the information on the stock prices. In an efficient market, stock prices should fully, promptly, and quickly capture all the information. Instead, the market shows phenomena of an under-reaction and over-reaction for both the short and the long run. The mergers and acquisitions （M＆As） are examples of anomalies. Often, the bidder companies record the negative abnormal returns for both the short and the long run. In contrast to the efficient market theory, the empirical evidence shows that this phenomenon is widespread in all （or most of） the countries of the world. This work examines the long-run performance in M＆As. For this purpose, 40 bidders were observed in Italy during the period of 1994-2008 among listed companies. The buy and hold abnormal returns （BHARs） methodology was used, with which it was possible to observe the returns for three years following the deal.

IPO initial returns in China: Underpricing or overvaluation?

This paper separates the amount of IPO underpricing(primary market underpricing) and overvaluation(secondary market overvaluation) from the value of an IPO's initial return to evaluate the relative importance of these two factors and their main determinants. Using data on the IPOs of 948 Chinese firms, we find that average initial returns are 66% and that underpricing and overvaluation are between 14–22% and 44–53%, respectively, depending on the method used to assess firms' intrinsic values. In addition, while both the value of the initial return and the extent of overvaluation are significantly negatively related to post-IPO long-run stock performance, overvaluation can predict post-IPO performance better than the value of the initial return. Value uncertainty in IPOs is positively related to both underpricing and overvaluation, and both the underwriter's reputation and the existence of pricing regulation are positively related to underpricing. Investor sentiment has a positive effect on overvaluation but has no effect or a negative effect on underpricing. Overall, our results suggest that in China overvaluation accounts for a larger proportion of the initial return than underpricing,and that underpricing and overvaluation have different determinants.