• A backstop is the act of providing extreme assistance or security in an offering of securities to an unsubscribed portion of the shares.

  • When a company attempts to raise capital through an issue, it may be refused by an underwriter or a major shareholder such as an investment bank to purchase any of its unsubscribed shares.
  • Return stops function as a kind of “insurance” and support for the entire offer, ensuring that the offer does not fail if all shares are not subscribed.