Definition of 'Stock Power'
A legal power of attorney form that transfers the ownership of certain shares of a stock to a new owner. A stock power transfer form is normally only required when an owner opts to take physical possession of securities certificates, rather that holding securities with a broker. A stock power form includes the previous owner's name, a description of the shares to be transferred, the stock certificates and the cost basis of the shares which normally requires a signature guarantee to protect against fraudulent transfers.
A stock power form is sometimes referred to as a security power form.
Investopedia explains 'Stock Power'
Most often, when buying or selling shares of stock, a retail investor uses a brokerage firm that will take care of any legal documentation required for the transfer of shares to the new owner. Thus, in the vast majority of cases, the owner of the shares of a stock does not take possession of the share certificates and does not have to complete legal paperwork in order to buy and sell shares.