In financial markets, a share's a unit of account for various financial instruments including stocks (ordinary or preferencial), and investments in limited partnerships, and REIT's. The common feature of all these's equity participation (limited in the case of preference shares). National variations United States In American English, the plural stocks's widely used instead of shares, in other words to refer to the stock (or perhaps originally stock certificates) of even a single company. Tradit… (More on Shares)