Debt limit crisis looms over US economy as showdown approaches.

Wall Street investors are growing increasingly concerned about the possibility of a government default on its debt as the deadline to raise the nation's $31.4 trillion debt ceiling approaches with no deal in sight. The cost of insuring against a U.S. default rose to its highest level in over a decade on Thursday, and bank executives are growing more concerned about the state of play in Washington but remain unsure how to inject themselves into the debate. The level of confidence of Wall Street investors can serve as the strongest force to drive Washington partisans to make a deal, as their financing of the country's enormous debt is crucial.