Stock market today: Dow, S&P 500, Nasdaq resume sell-off, oil surges as Middle East conflict escalates

US stocks moved firmly lower on Thursday as oil prices pressed higher amid signs that the Iran war is spreading across the Middle East, further threatening to disrupt energy supplies.

The Dow Jones Industrial Average (^DJI) led the way down with a loss of around 1.1%, or over 500 points, following a second straight mostly down day on Wall Street. The Nasdaq Composite (^IXIC) fell by 1.2%, and the S&P 500 (^GSPC) dropped 1%.