我国主板、中小板和创业板股票IPO抑价比较研究

以2009年恢复新股发行至2012年IPO新规出台为节点，基于曼一惠特尼U检验和独立样本t检验分别对新规出台前后的主板、中小板、创业板IPO抑价率进行了计算与比较检验。结果显示，在2009至2012年新规出台前，主板与中小板、主板与创业板的IPO抑价率之间存在显著差异，中小板与创业板之间IPO抑价率不存在显著差异；2012年新规出台后三个市场之间的IPO抑价率差异性不显著。2012年IPO新规出台前后，主板自身的IPO抑价率均不存在显著差异，与中小板和创业板的IPO抑价率均存在显著差异。

A Comparative Study on the IPO Underpricing in Chinese Stock Market

The study compares the IPO underpricing on the Main Board market, SME Board market and GEM Board market. The period of the inspection is from the year 2009 when the IPO re-started to the year 2012, and it is divided into two parts by the time when the new policy of IPO was published. The study shows that the IPO underpric- ing on the Main Board market is different from that on the SME Board market and the GEM Board market, and there is no difference between SME Board market and the GEM Board market during the first period. In the second period, the study shows that there are no differences among these three markets. According to the comparisons of these three mar- kets themselves, the conclusions are that there is no difference on the main board market. However on the SME Board market and the GEM Board market, there are obvious differences in the underpricing circumstance.