The Dow Jones Industrial Average turned sharply lower on Friday, adding to its rout on Thursday, as shares of Goldman Sachs Group Inc. GS, -2.91% and 3M Co. MMM, -3.50% picked up momentum. Those Dow DJIA, -1.77% components were contributing nearly 90 points to the price-weighted gauge's tumble. The average was most recently off 300 points, or 1.3%, at 23,662, with selling intensifying with less than an hour remaining in regular trade. The S&P 500 index SPX, -2.10% was down 1.6% at 2,602, while the Nasdaq Composite Index COMP, -2.43% gave up 1.8% at 7,043, to fall below firmly below its 100-day moving average around 7,082, a bearish sign for the technology-laden equity gauge. Wall Street investors have been fretting over the potential for a trade war between China and the U.S.