Greenshoe

Greenshoe option is a special provision in an IPO prospectus, which allows underwriters to sell investors more shares than originally planned by the issuer. This would normally be done if the demand for a security issue proves higher than expected. Legally referred to as an over-allotment option. A greenshoe option (sometimes green shoe, but must legally be called an "over-allotment option" in a prospectus) allows underwriters to short sell shares in a registered securities offering at the offering price. The greenshoe can vary in size and is customarily not more than 15% of the original number of shares offered.