Goldman, along with the Citadel hedge fund and Knight Capital Group, owns Direct Edge, a broker-dealer that provides one-stop shopping by aggregating orders and using 10 of the most active dark pools to execute orders.

FORBES: Watch Out For The Quants

When Arcelor resisted and turned to a white knight in Russia, Goldman rallied support for Mittal's bid among hedge funds and other big investors, as well as with politicians in Brussels and elsewhere.

FORBES: On The Cover/Top Stories

Knight's Direct Edge got a minority investment earlier this month from Chicago-based hedge fund Citadel.

FORBES: Crank Up The Volume

Michael Hintze might run a big and successful hedge fund, enjoy a view of Buckingham Palace's gardens from his office and boast the title of papal knight.

FORBES: Magazine Article