A bearer instrument is a document that entitles the holder of the document rights of ownership or title to the underlying property, such as shares or bonds. Bearer instruments differ from normal registered instruments, in that no record is kept of who owns the underlying property, or of the transactions involving transfer of ownership. Whoever physically holds the bearer document is assumed to be the owner of the property. This is useful for investors and corporate officers who wish to retain anonymity, but ownership (or legal entitlement) is extremely difficult to establish in event of loss or theft.