U.S. Stocks Open Lower on North Korea Tensions; Apple Sinks on iPhone Worries

U.S. stocks tumbled at the open on Wednesday, following a worrisome hydrogen bomb test in North Korea. Meanwhile, encouraging labor market data was released from ADP, showing the economy added 257,000 jobs in the private sector in December, ahead of expectations. The government's December jobs report is released Friday. 'We often say that the ADP is kind of a benchmark for the jobs report and the non-farm payrolls at the end of the week, but it doesn't necessarily ever work out that way,’ said James Hughes, chief market strategist at GKFX, based in London. Economists expect non-farm payrolls to rise by 200,000. Shares of Apple (AAPL) were in focus this morning as investors worry about how much room for growth its iPhone has left. Reports suggest Apple is looking to build fewer iPhones. Agriculture company Monsanto (MON) posted first quarter results this morning. On the bottom line, Monsanto reported an adjusted net loss of $0.11 a share, while analysts were expecting a deeper loss of $0.22 a share. Revenue fell 23 percent, missing expectations on lower demand of its corn seeds. TheStreet’s Scott Gamm reports from Wall Street.