IPO Advertising: A Possible Cause of Short-Term Overvaluation

Abstract

This research investigated the market conditions caused by IPO advertising by examining the impact of IPO advertising, based on the US stock market from 1986 to 2009. The relationship between advertising intensity in the IPO year and the degree of IPO underpricing was examined. It was found that an increase in advertising intensity around an IPO event increases the initial returns. Simultaneously, however, advertising intensity around an IPO event also increases the degree of overvaluation, which raises the question as to whether advertising serves primarily as a mechanism to convey a firm’s true value to investors. The theoretical valuation of IPO and the relation between IPO advertising and the degree of stock overvaluation are discussed. Based on the Peasnell’s (1982) residual-income valuation framework (henceforth RIV), IPO advertising was proved to cause stock price to be more overvalued in the secondary market: a positive relationship was found between advertising and the degree of stock overvaluation relative to its theoretical value. Accordingly, an alternative hypothesis, that advertising inflates the short-run stock price, was proposed. The results of this study are consistent with the view of Purnanandam and Swaminathan (2004), namely that the stock price of newly listed firms can be overvalued.

Citation

Dumrongwong, K. (2016), "IPO Advertising: A Possible Cause of Short-Term Overvaluation", The Spread of Financial Sophistication through Emerging Markets Worldwide (Research in Finance, Vol. 32), Emerald Group Publishing Limited, Leeds, pp. 145-163. https://doi.org/10.1108/S0196-382120160000032006