The market in shares not listed on the Stock Exchange.
Over the Counter, the term used to describe the trading of futures and options outside a regulated stock exchange. Trade is directly between buyers and sellers and there is no standardization of strikes or expirations.
(OTC) Market where traders are connected through computer networks and telephones and conduct trading through these mechanisms rather than on the floor of an exchange. Rules for OTC trading are written and enforced by the National Association of Securities Dealers (NASD) in the U.S.