A type of securities registration whereby an underwriter allows existing holders of shares in a company to register their shares when the company’s other securities are being registered (typically through offering of new public shares). Piggyback registration confers on existing shareholders the right to sell their holdings in conjunction with an offering of new shares. More specifically, holders of restricted stock in a public company are given the right to participate in a public offering underwritten by a group of investors.  The prospectus in a piggyback registration will set out the nature of such a public/private share offering and specify the sellers of the private shares.