Why do securityholders require a Medallion Stamp or signature guarantee?

A signature guarantee provides the transfer agent and issuer with proof that the registered owner of the security wants to transfer the security. There are two ways to guarantee a security in Canada: A Schedule I Canadian Chartered Bank can guarantee signatures and is represented by a stamp from the financial institution. The guarantee is signed by an officer providing proof that the signature is genuine. The officer will also present their bank ID number. A financial institution (broker, dealer, etc.) may provide a Medallion Signature Guarantee supported by a recognized Security Transfer Association Medallion Program. This guarantee offers proof that the signature is real.