The Effects of Ambiguous Information on Initial and Subsequent IPO Returns

Newly public companies must disclose significant risk factors in the offering prospectus. These disclosures are examples of "soft" or ambiguous information. Ambiguity models predict that investors will alter their portfolio weights and react to subsequent signals about such information. We test for these effects in a sample of 1,398 initial public offerings (IPOs) using word count ratios between soft and hard information as measures of ambiguity. We find a significant relationship between the soft information on risk and both initial and ex post measures of returns. These results support the view that soft information embeds ambiguity and that it influences investors' portfolio choices.