This paper examines the effect of several factors on the market share of investment banks that act as book managers in initial public offerings (IPOs) between 1984 and 1995. For established banks, IPO first-day returns, one-year abnormal performance, abnormal compensation, industry specialization, analyst reputation, and association with withdrawn offers have a significant impact on changes in market share. These factors have a more significant effect on market share changes in low-volume IPO markets. These factors have a less significant effect on market share, statistically and economically, for less established banks, consistent with the notion that less reputation is placed at risk.

This paper examines policies and procedures put in place by corporations to regulate trading in the stock by the firm's own insiders. Over 92% of our sample companies have their own policies restricting trading by insiders, and 78% have explicit blackout periods during which the company prohibits trading by its insiders. Our data indicate that blackout periods successfully suppress trading, both purchases and sales, by insiders, and that the blackout period is associated with a bid–ask spread that's narrower by about two basis points. Consistent with this effect on the spread, allowed insider trades are modestly more profitable than insider trades made during prohibited blackout periods.