By ALEX VEIGAA late rise saved the stock market from a third straight day of losses. The push was enough to nudge the Standard & Poor's 500 index into the green by half a point Wednesday, as investors bought up oil refiners, mining companies and technology stocks. Refiners such as Tesoro Corp. led the gains. Stocks were down for most of the day, but began to crawl back in the afternoon. The S&P 500 index added 0.57 points, or 0.03 percent, to close at 1,868.20. The Nasdaq composite also rebounded. It gained 16.14 points, or 0.4 percent, to 4,323.33. Only the Dow Jones industrial average ended lower. It fell 11.17 points, or 0.1 percent, to 16,340.08. The three major U.S. stock indexes are still down for the week. Investors have been worried about a sharp drop in China's exports reported over the weekend, which raised concerns that the world's second-largest economy is slowing. Since China is a big consumer of raw materials and energy, commodities such as copper and iron ore have dropped sharply. The S&P 500 index ended lower Monday and Tuesday. Some strategist say investors are pausing after the market hit three record highs last week. "When markets reach these kind of new highs very often they have to digest those gains, which is what they're doing," said Quincy Krosby, a market strategist with Prudential Financial. "They need to adjust the gains and then wait for the next catalyst to move higher." That could come Thursday, when new data on retail sales and weekly unemployment benefit applications are released. On Friday, a survey of consumer confidence should give traders a better sense of how Americans feel about the economy. Among the big winners Wednesday was Tesoro. It rose the most of any stock in the S&P 500 index, climbing $2.13, or 4.1 percent, to $54.50. Marathon Petroleum Corp., added $3.21, or 3.5 percent, to $94.50, while Valero Energy Corp., gained $1.62, or 3 percent, to $55.29.