Pseudo market timing and the long-run underperformance of IPOs

Numerous studies document long-run underperformance by firms following equity offerings. This paper shows that underperformance is very likely to be observed ex-post in an efficient market. The premise is that more firms issue equity at higher stock prices even though they cannot predict future returns. Ex-post, issuers seem to time the market because offerings cluster at market peaks. Simulations based on 1973 through 1997 data reveal that when ex-ante expected abnormal returns are zero, median ex-post underperformance for equity issuers will be significantly negative in event-time. Using calendar-time returns solves the problem.