Dow Sinks Again As President Urges Calm

The Dow Jones Industrial Average closed below the 11,000 mark Monday. President Obama sought to calm the market jitters, saying the downgrade was not about the nation's fiscal soundness, but about its political impasse.

It was the first time the Dow fell below 11,000 since November and its biggest one-day point drop since December 2008.

NPR's complete coverage of the economic challenges includes an outline of how the S&P assigns debt ratings, how the U.S. credit downgrade affects foreign markets and in depth analysis from the NPR Planet Money team.