Instinet Incorporated is an institutional, agency-model broker that also serves as the independent equity trading arm of its parent, Nomura Group.

The founders aimed to compete with the New York Stock Exchange by means of computer links between major institutions, such as banks, mutual funds, and insurance companies, with no delays or intervening specialists.

[2] Through the Instinet system, which went live in December 1969, the company provided computer services and a communications network for the automated buying and selling of equity securities on an anonymous, confidential basis.

By the time that the U.S. Securities and Exchange Commission introduced the Order Handling Rules and alternative trading systems (ATS) regulation in the late 1990s.

By the early 2000s, these competitors, helped by missteps at Instinet that included rapid expansion, over-spending and slow uptake of technology, had managed to erode the firm's market share.

In December 2009, in commemoration of its 40th anniversary, Instinet worked with the Make-a-Wish Foundation to grant wishes to 40 children with life-threatening illnesses.

[14] However, in September 2012, Nomura announced that it would instead make Instinet its execution services (cash, program and electronic trading) arm in all markets globally excluding Japan.