[6][7] Getco LLC was founded in 1999[8] by Stephen Schuler and Daniel Tierney, former floor traders in Chicago, and had 400 employees at the time of the merger.

Its largest business was market-making in US equities for retail brokerages, though it also provided other services such as electronic execution, dark pools, plus institutional sales and trading.

In August 2012, a technological/managerial breakdown subsequently dubbed the "Knightmare" caused Knight to lose $460m in the course of one trading day, nearly putting the firm out of business.

[4] On July 8, 2013, chief executive officer Daniel Coleman rang the opening bell at the New York Stock Exchange, marking the completion of Knight and Getco's merger and the unveiling of a new corporate identity, KCG Holdings.

[13] In April 2017, Virtu Financial announced that it would purchase KCG Holdings for US$1.4 billion in cash.