A name for a security that is not listed on an exchange. The OTC is the major trading market for all US bonds, as well as many small- and large-capitalization stocks. Whereas non-OTC stocks trade on the floor of actual stock exchanges, OTC issues are traded via telephone and computer networks connecting dealers in stocks and bonds. The dealer may or may not be a member of a securities exchange, but he or she must be a member of the FINRA.