This paper explores the impact of investor sentiment on IPO pricing. Using a model in which the aftermarket price of IPO shares depends on the information about the intrinsic value of the company and investor sentiment, I show that IPOs can be overpriced and still exhibit positive initial return. A sample of recent French offerings with a fraction of the shares reserved for individual investors supports the predictions of the model. Individual investors' demand is positively related to market conditions. Moreover, large individual investors' demand leads to high IPO prices, large initial returns, and poor long-run performance. THE END OF THE NINETIES was one of the hottest IPO markets ever. In this period, both the number of initial public offerings and the level of initial returns have reached unprecedented peaks. Ritter 1 documents that in 1999 and 2000 only, 803 companies went public in the United States, raising about $123 billion and leaving about $62 billion on the table in the form of initial returns. Periodically, such periods of IPO euphoria occur. These so-called "hot issue" markets are characterized by high IPO volumes and high levels of initial return (see Ibbotson and Jaffe (1975) and Ritter (1984)), as well as positive serial correlation of IPO initial returns and correlation between recent levels of initial return and current IPO volume.Surprisingly, however, pre-IPO shareholders do not seem to be upset about leaving so much money on the table. Loughran and Ritter (2002) explain this phenomenon by the fact that insiders of IPO companies consider not only the shares they sell in the IPO, but also those they retain, which benefit from the large initial price run-up. Ljungqvist and Wilhelm (2003) show that during the 1999 to 2000 period, IPO companies were significantly different from usual * François Derrien is at the Rotman School of Management, University of Toronto. This article is a substantially revised version of one chapter of my dissertation at HEC.