Book Building and Fixed Price Issue are the two types of Initial Public Offerings (IPO s) through which a corporate can raise money in the capital market that aids price and demand discovery. It is a process used for marketing a public offer of equity shares of a company. It is a mechanism where, during the period for which the book for the IPO is open, bids are collected from investors at various prices, which are above or equal to the floor price. The process aims at tapping both wholesale and retail investors.
The offer/issue price is then determined after the bid closing date based on certain evaluation criteria.

In a book building public issue the bids are received at different price levels and the demand for the issue is built up over a period of time. Depending upon the bids received at different price levels the issue price is ascertained. In a fixed price issue the issue price is pre ascertained by the issuer.