We examine whether risk, timing or mispricing hypotheses can explain the underperformance of private and public equity issuers, in Canada, where both categories share several common characteristics. Adding an investment risk factor to the TFPM reduces, but does not eliminate, the underperformance. Four arguments, including financial constraints and poor operating performance, do not support the timing hypothesis. Our results for their part support the mispricing hypothesis. The market correctly assesses the investment projects of value firms, but tends to overestimate those of glamour firms. For both types of issues, the underperformance is explained by investors' overoptimism relative to glamour/high-investment firms.