Underpricing of initial public offerings: The case of Portugal

This paper analyzes the initial public offering (IPO) underpricing phenomenon in Portugal. We show that the 'hot issue' market of 1987, coinciding with a speculative bubble in the stock market, is well explained by investor sentiment theories and that the issuing firms seized a 'window of opportunity' provided by excessive demand to offer and list their shares. In IPOs prior to the 1987 crash, underpricing is very high while there is a strong reversion to fundamentals in the long run. In the period 1988-2004, we find lower IPO underpricing and overall no evidence of long-run underperformance of IPO firms. Bookbuilding IPOs are more underpriced than other price setting systems IPOs, and firms with seasoned public offerings show abnormal returns in the long run. © International Atlantic Economic Society 2006.