When a company wants to raise more funds by issuing additional securities, it may give its stockholders the opportunity, ahead of others, to buy the new securities in proportion to the number of shares each owns. The piece of paper evidencing this privilege is called a right. Because the additional stock is usually offered to stockholders below the current market price, rights ordinarily have a market value of their own and are actively traded. In most cases they must be exercised within a relatively short period. Failure to exercise or sell rights may result in monetary loss to the holder. (See: Warrants)