are common shares
that have been authorized, issued, and purchased by investors. They have voting rights and represent ownership in the corporation by the person or institution that holds the shares. They should be distinguished from treasury shares
, which are common stock repurchased by the corporation. Treasury shares decrease outstanding shares.
Shares outstanding can be calculated as either basic or fully diluted, with the effect of such diluting securities as options or convertibles. Shares outstanding can be obtained from quarterly filings with the SEC.