Third market in finance, refers to the trading of exchange-listed securities in the over-the-counter (OTC) market. These trades allow institutional investors to trade blocks of securities directly, rather than through an exchange, providing liquidity and anonymity to buyers[1]
Third market trading was pioneered in the 1960s by firms such as Jefferies & Company although today there are a number of brokerage firms focused on third market trading, and more recently dark pools of liquidity.[2]