"The Dow Jones Industrial Average closed 236 points lower, or 0.6% and posted its biggest one-day loss since early December. The S&P 500 also had its worst day in a month, sliding 0.5%. The Nasdaq Composite dropped 0.8%. The Dow briefly dropped more than 360 points at the open. The major averages recovered some ground later in the session as oil prices came off their lows. "