In an
issue of new
stock, a guarantee made by an
investor, usually an institution, to a
publicly-traded company that it will
buy the remainder of an issue if the company is unable to
place it all with other investors. For example, an institution may announce that it will provide 100% back stop to a company's new issue up to $50 million. If the company only raises $35 million by placing the
security with other investors, the institution will buy the remaining $15 million worth of stock.