Abstract: Under market-oriented pricing mode, the adjustment of IPO pricing is a common phenomenon. Based on theoretical analysis and the samples of 348 IPO companies with market-oriented pricing from November 1, 2010 to April 27, 2012, this paper examines the impact of IPO pricing adjustment on participant welfare. It is found that the majority of IPO pricing tends to increase, and the welfare effects are as follows. Issuers earn higher financing revenue. Underwriters charge more commissions. Although the earnings are relatively reduced, institutional investors, strategic investors and successful applicants can still get higher welfare increase. Retail investors are the main body of speculation and suffer welfare losses, but the loss is not due to the adjustment of IPO pricing.

Key words: IPO, investor, IPO pricing adjustment, welfare effect