Definition of 'Book Runner'
The main underwriter or lead manager in the issuance of new equity, debt or securities instruments. In investment banking, the book runner is the underwriting firm that "runs," or who is in charge, of the books. A large, leveraged buyout could involve multiple companies, and the book runner works with the other participating firms. Typically, one company takes the responsibility of "running" or handling the books, and the book runner is listed first among the other underwriters participating in the issuance. More than one book runner can manage a security issuance, in which case the involved parties are called "joint book runners."
Also called managing underwriter or syndicate manager.
Investopedia explains 'Book Runner'
In investment banking, a syndicate is comprised of a group of underwriters who are responsible for placing a new equity, debt or security issue with investors. The book runner typically assigns parts of the new issue to other underwriting firms for placement, while keeping the largest part for itself. The book runner syndicates with other underwriting firms in order to reduce its risk in the issuance of the new equity, debt or security.