security (finance)

A security, in a financial context, is a certificate or other financial instrument that has monetary value and can be traded.  

Securities are generally classified as either equity securities, such as stocks and debt securities, such as bonds and debentures. The sale of securities to investors is one of the primary ways that publicly-traded companies  drive new capital for operations.

In the United States, the Securities and Exchange Commission (SEC) oversees securities transactions, activities of financial professionals and mutual fund trading to prevent fraud and intentional deception.

See also: quiet period, earnings season, blackout period