When IPO shares are sold sequentially, later potential investors can learn from the purchasing decisions of earlier investors. This can lead rapidly to "cascades" in which subsequent investors optimally ignore their private information and imitate earlier investors. Although rationing in this situation gives rise to a winner's curse, it is irrelevant. The model predicts that: (1) Offerings succeed or fail rapidly. (2) Demand can be so elastic that even risk-neutral issuers underprice to completely avoid failure. (3) Issues with good inside information can price their shares so high that they sometimes fail. (4) An underwriter may want to reduce the communication among investors by spreading the selling effort over a more segmented market.

When IPO shares are sold sequentially, later potential investors can learn from the purchasing decisions of earlier investors. This can lead rapidly to “cascades” in which subsequent investors optimally ignore their private information and imitate earlier investors. Although rationing in this situation gives rise to a winner's curse, it is irrelevant. The model predicts that: (1) Offerings succeed or fail rapidly. (2) Demand can be so elastic that even risk‐neutral issuers underprice to completely avoid failure. (3) Issuers with good inside information can price their shares so high that they sometimes fail. (4) An underwriter may want to reduce the communication among investors by spreading the selling effort over a more segmented market.

An informational cascade occurs when it is optimal for an individual, having observed the actions of those ahead of him, to follow the behavior of the preceding individual without regard to his own information. We argue that localized conformity of behavior and the fragility of mass behaviors can be explained by informational cascades.

An informational cascade occurs when it is optimal for an individual, having observed the actions of those ahead of him, to follow the behavior of the preceding individual without regard to his own information. We argue that localized conformity of behavior and the fragility of mass behaviors can be explained by informational cascades.