Securities

Securities are ownership interests in companies and include shares of corporate stock or mutual funds, bonds issued by corporations or governmental agencies, stock options and other derivative securities, limited partnership units, and various other formal "investment instruments."

Banknotes, checks, and bills of exchange do not fall into this category. Securities that have already been issued may also be traded; this trading is called the aftermarket.

In the U.S., dealing in securities is heavily regulated by both the federal authorities (chiefly the S.E.C.) and state authorities.

See also: Financial markets, Financial supervision, Finance