Greenshoe, or an "over-allotment option", is the term commonly used to describe a special arrangement in a share offering, for example an initial public offering (IPO), which enables the investment bank representing the underwriters to support the share price after the offering without putting their own capital at risk. The option is codified as a provision in the underwriting agreement between the leading underwriter, the lead manager, and the issuer (in the case of primary shares) or vendor (secondary shares). The provision allows the underwriter to purchase up to 15% in additional company shares at the offering share price.