Book Building

Book building is the dominant method for pricing IPOs in the United States and most major international markets. The process begins after the SEC has declared the registration statement effective and the company enters the marketing phase of the offering. The underwriter opens an electronic order book and invites qualified institutional investors — mutual funds, hedge funds, pension funds, insurance companies, and sovereign wealth funds — to submit indications of interest specifying how many shares they would purchase at various price points.

These indications are not binding commitments; they are expressions of interest that the underwriter aggregates to understand the shape of demand across a range of prices. The underwriter analyzes the book to determine where demand is strongest, what price would allow the full offering to be sold, and whether certain investors are price-sensitive (willing to buy only below a certain level) or price-insensitive (willing to buy at any price within the range).

Alongside book building, the company and underwriters conduct a roadshow — a series of meetings with large institutional investors — to pitch the investment thesis. Feedback from these meetings informs adjustments to the preliminary price range disclosed in the prospectus. If demand is robust, underwriters may raise the price range; if demand is weak, they may lower it or reduce the size of the offering.

Once the book is sufficiently covered and the final price is determined, the underwriter allocates shares. Institutional investors who provided the most useful price feedback, who have a long-term investment orientation, or who are existing relationships of the underwriting bank often receive larger allocations. Retail investors access IPO shares through their brokerage accounts, but allocations to retail investors are generally smaller relative to institutional demand.

The book-building process has been criticized for favoring institutional over retail investors, and for creating systematic underpricing. Some economists estimate that underpricing in U.S. IPOs leaves an average of 15% to 20% in what is called money on the table — proceeds the company could have raised but did not because shares were priced below where they ultimately traded. This has fueled interest in alternative mechanisms such as Dutch auctions and direct listings.