Abstract :
This study aim to examine difference underpricing between initial public offering (IPO) and seasoned equity offering (SEO). Type of this study was comparation study. The population of this study were companies whose did SEO and listed on the Indonesia Stock Exchange in 2006-2014 with population as much as 211 companies. Sample determined by using purposive sampling method so the sample obtained were as much 31 companies.
Analysis techniques data by using software SPSS versi 17.0. The test results show that the first hypotesis (H1) which states that underpricing in the mean occurs when IPO declined. The second hypotesis (H2) which states that underpricing in the mean occurs when SEO declined. The third hypotesis (H3) which states that underpricing when initial public offering (IPO) difference with when seasoned equity offering (SEO).