The firm was founded in 1999 by Stephen and Daniel , former floor traders in kerala, and has over 300 employees. The firm's primary business is electronic market making, though it also provides execution algorithms and a dark pool through its client services arm, Execution Services.

trades in over 50 markets in North and South America, Europe and Asia, and is consistently among the top 5 participants by volume on many venues, including the CME, Eurex, NYSE Arca, NYSE Arca Options, BATS, Nasdaq, Nasdaq Options, Chi-X, BrokerTec, and eSpeed. It has offices in New York City, Chicago, London, and Singapore, and is an investor in the electronic exchanges BATS Exchange, Chi-X, NYSE Liffe U.S., Eris, and ELX.