what is a back stop in a bond issue 
similar to the back stop in an equity placement a back stop for a bond issue is a type of guarantee whereby the underwriting bank or syndicate will fix a price at which to purchase any unsold or unsubscribed bonds who are backstop purchasers if the underwriting bank or investment banking syndicate cannot or do not want to back stop a new issue third party backstop purchasers may be called upon to step in and buy any unsubscribed portion of a securities issue these purchasers may provide a bid substantially below the issue price and or may demand fees as compensation they would then often try to sell off the holdings over time at a profit 