Over-subscription of IPO:

最初的公开产品通常被低估。由于承销商希望迅速售罄，因此他们有动力低估了新证券。以所提供的价格超出了需求，即需求通常超过供应。换句话说，问题被超额认购。而不是将价格提高到均衡水平，而是具有广泛的配给。通常，以要约价格的需求过剩，股票对投资者进行了配给。所有知情和不知情的投资者均配给。观察到的知情投资者的配给与我们的直觉背道而驰，原因有两个。首先，它与假定的最佳IPO机制相矛盾，即在有知情的竞标者中，那些具有较高信号的人会在提供较低信号的投标人之前获得全部分配。

Second, it seems to contradict profit-maximization on the part of the seller. There is little evidence about who benefits from IPO underpricing and why. Do institutions receive larger allocations than individual investors? Do institutions concentrate on the most underpriced offerings because they are better informed than individual investors or because underwriters use their superior knowledge to intentionally favour their long-term clients? If, on the other hand, allocations to institutional investors are unrelated to first day returns, is it because institutions lack superior ability or because allocations of coveted underpriced shares carry the obligation of participating in overpriced issues? There have been reports of scandals in the allocation of heavily underpriced offerings.