IPO Post-Issue Markets: Questionable Predilections But Diligent Learners?

Efficiency in the IPO (Initial Public Offering) aftermarket is tested without imposing any restrictions on the priors about potential default at the issue date. Merging Ritter's extended dataset (which covers the period 1975-84) with the CRSP tapes, IPOs are followed up to ten years after issue. Across all IPOs, or when stratifying IPOs according to issue underpricing, industry affiliation or rank of entry in an industry, little evidence against rational price behavior is found. In contrast, the market clearly over-reacts to information about the eventual fate of low-priced issues. A suggestive relationship between irrational price behavior and subsequent takeover activity is uncovered.