 Book building is an alternative method of making a public issue in which applications are accepted from large buyers such as financial institutions, corporations or high net-worth individuals, almost on firm allotment basis, instead of asking them to apply in public offer.Book building is a relatively new option for issues of securities, the first guidelines of which were issued on October 12, 1995 and have been revised from time to time since.Book building is a method of issuing shares based on a floor price which is indicated before the opening of the bidding process.