instinet means: A computerized subscriber service, which serves as a platform for the fourth market. The SEC has registered “Instinet”. It is a stock exchange that lists a number of institutional and mutual fund investors. Subscribers can display offers and bids which are visible system-wide for any length of time specified by the initiating party and then to execute trades electronically. Market makers use Instinet most often, however, customers and non-market makers have equally access to the system. (in Stock Market Dictionary)