19c3 Stock

Any stock listed on an equity exchange after April 26, 1979. This classification allowed members of exchanges to trade these stocks off the board (not at the exchange). The classification of a 19c3 stock refers to SEC rule 19c3 (the regulation that allowed off-board transactions to be made).

Investopedia Says:
Prior to April 26, 1979, members of the major exchanges (ie. the NYSE) were not allowed to conduct stock trades in situations that where they were not physically at an exchange. This meant that OTC trades could not have legally occured. The designation of 19c3 stock was the first step toward the creation of the National Market System.

Related Links:
Find out how this regulatory body protects the rights of investors. Policing The Securities Market: An Overview Of The SEC