Stocks closed lower for the first time this week but still had their best weekly gain since June. Technology companies did worse than the rest of the market. Stocks are coming off a four-day rally as traders tempered their worries about economic fallout from the virus outbreak that originated in China. The S&P 500 index fell 18 points, or 0.5%, to 3,327, a day after hitting a record high. The Dow Jones Industrial Average fell 277 points, or 0.9%, to 29,102 and the Nasdaq lost 51 points, or 0.5%, to 9,520. Bond prices rose. The yield on the 10-year Treasury fell to 1.58%.