Wall St. drops amid worry over North Korea test, rate outlook

U.S. stocks sold off on Friday, putting the S&P 500 on pace for its worst day in over two months as investor nervousness increased following a nuclear test by North Korea and comments by Federal Reserve officials that hinted at a U.S. interest rate hike. North Korea conducted its fifth and biggest nuclear test on Friday and said it had mastered the ability to mount a warhead on a ballistic missile, drawing condemnation from the United States as well as China, Pyongyang's main ally.