* U.S. stocks closed higher across the board; * Moody's downgrades U.S. credit rating to Aa1; * Consumer confidence index fell to the second lowest in history. On Friday, the three major U.S. stock indexes closed higher across the board, with the Dow turning higher during the year and the S&P 500 recording five consecutive positive days. On the one hand, the market expects the global trade situation to get more clear signals in the coming weeks, which will push the market to rebound; On the other hand, the University of Michigan's consumer confidence index fell short of expectations, narrowing the gains of major stock indexes. As of the close, the Dow rose 331.99 points, or 0.78%, to close at 42,654.74 points; The Nasdaq rose 98.78 points, or 0.52%, to close at...

