The term "stock options" is used broadly to include not only options on common stocks but also options on all other types of equity securities, such as limited partnership interests, "American Depository Receipts" and "American Depository Shares" representing interests in foreign entities, and preferred stocks. Options are available on exchange-traded equity securities, on unlisted equity securities traded in the NASDAQ stock market and designated as national market system securities, and on equity securities traded both in the NASDAQ stock market and on exchanges. The NASDAQ stock market is primarily an inter-dealer trading system as contrasted with exchange auction markets.
Issuers of underlying equity securities do not participate in the selection of their securities for options trading (although some options markets may determine not to select an underlying security without the consent of the issuer of that security). Issuers of underlying equity securities have no responsibility regarding the issuance, the terms, or the performance of options, and option holders have no rights as security holders of such issuers.