The amount of initial public offering (IPO) securities that is allocated to each underwriter (if two underwriters or more are involved in the process). After the issued is closed, bids received are segregated into different categories (as per the type of investors: retail, institutional, non-institutional, etc). If the issue is oversubscribed, the oversubscription ratios for each category will be calculated vis-a-vis the shares assigned for each category. Bids within each category are then grouped under different buckets in accordance with the number of shares booked. The number of actual number of shares to be allotted in each category is:

Number of shares = shares booked x oversubscription ratio

The number of actual shares to be allotted is then determined for the whole issue.