ELX Futures, the upstart US derivatives market backed by a dozen of the most active dealers, increased its trading volumes by 30% last month and raised its market share to 3%, while continuing its spat with the CME Group, over a rule change that would boost its volumes further.

New York-based ELX, launched in July by a group that include Goldman Sachs and Getco, said investors traded over 50,000 of its four US Treasury futures each day during October, or 30% more than they did the previous month.