An unlisted security is a stock or other financial instrument that is not traded on a formal exchange. Rather, it trades in the over-the-counter (OTC) market. Unlisted securities are also called OTC securities. Market makers facilitate the buying and selling of unlisted securities in the OTC market.
Unlisted securities are usually issued by smaller or new firms that cannot or do not wish to comply with the listing requirements of an official exchange. Further, because they are not exchange traded, unlisted securities can be less liquid than listed securities.
Securities must meet a number of requirements to be listed on an exchange. For example, to be listed on an exchange such as the NYSE or AMEX, a publicly traded stock must represent a company that surpasses an annual income or market capitalization threshold. The company also must have issued a specific number of shares and be able to afford the exchange's listing fee, which often exceeds $100,000. These requirements ensure that only the highest quality companies trade on exchanges. Thus, unlisted securities may be of lower quality and present a greater risk to investors.