U.S. stocks on Thursday began trade near break-even levels, as investors attempted to shake off Wednesday’s about-face that saw the Dow erase a 200-point advance, partly based on worries about the Federal Reserve’s plan to shrink its $4.5 trillion balance sheet this year. The Dow Jones Industrial Average DJIA, +0.15% opened flat at 20,638, but tilting lower, the S&P 500 index SPX, +0.18% was about a point lower, or less than 0.1%, at 2,351, while the Nasdaq Composite Index COMP, +0.17% was steady at 5,867. Weighing on investors’ minds are concerns that President Donald Trump’s tax-reform plans will take longer than expected, as were jitters over a meeting between Trump and his Chinese counterpart Xi Jinping. On the economic front, a report on jobless claims showed that the number of Americans who applied for unemployment benefits last week sank by 25,000 to 234,000, marking the second-lowest level of the current economic expansion. The report comes ahead of the closely watched nonfarm-payrolls report due Friday and a health private-sector employment report on Wednesday. In corporate news, Amazon.com Inc. AMZN, -0.21% said it plans on hiring 30,000 part-time workers in 2018.