美股三大指数转跌，道琼斯指数跌0.16%，标普500指数跌0.15%，纳斯达克综合指数跌0.16%

Group 1 - The three major US stock indices turned negative on August 28, with the Dow Jones Industrial Average falling by 0.16% [1] - The S&P 500 index decreased by 0.15% [1] - The Nasdaq Composite index also dropped by 0.16% [1]