US stocks opened mildly higher Friday, ahead of a number of speeches from Federal Reserve officials, including Fed Chairman Ben Bernanke. Bernanke, who is going to resign by the end of January after his eight-year tenure as the U.S. central bank chief, is due to deliver a speech on the changing Fed at the American Economic Association at 2:30 p.m. local time. Investors are also expected to hear speeches from Fed Governor Jeremy Stein, Philadelphia Fed President Charles Plosser and Richmond Fed President Jeffrey Lacker later in the day. Major stock indices are on track to post a mixed picture for the week, as a negative start to the New Year on Thursday, the first trading day of 2014, dented a record rally earlier this week. Volume is likely to be low in a holiday shortened week, as the U.S. stock market was closed on Wednesday for New Year' s Day. A massive snow storm in the northeast of the United States could also affect trading volume. In corporate news, a number of automakers will post their vehicle sales data in December during the day, including those from Ford Motor and General Motors. Shortly after Thursday' s opening bell, the Dow Jones Industrial Average gained 44.71 points, or 0.27 percent, to 16,486.06. The S&P 500 rose 4.08 points, or 0.22 percent, to 1,836.06. The Nasdaq added 6.39 points, or 0.15 percent, to 4,149.46.