what is a book runner 
a book runner is a primary underwriter or lead coordinator in issuing new equity debt or securities instruments these types of underwriters also may coordinate with others to mitigate their own risk for example those representing companies in large leveraged buyouts lbos because they combine the duties of an underwriter while coordinating the efforts of multiple involved parties and information sources book runners become the central point for all information regarding the potential offering or issue the bottom linean underwriter is any party usually part of a larger financial organization that evaluates and assumes for a fee another party s risk in mortgages insurance loans or investments underwriters work in many areas of finance from the insurance industry to mortgage lending they are critical to the mortgage industry insurance industry equity markets and common types of debt securities trading because of their ability to ascertain risk 