A group of U.S. banks is urging clearinghouses to divulge how they'll invest the margins that banks will have to put up under rules for over-the-counter derivatives and how they'll protect their members from defaults. "The ultimate goal is that clearing member banks will not only have the tools and data necessary to better evaluate specific risks that they face, but that in so doing all market participants will better understand the unique and critically important role played by" clearinghouses, according to a report from the group.