US stocks dropped on Friday, giving the S&P 500 its worst day since June's Brexit vote. 
The Dow Jones industrial average was down 394.46 points, or 2.13 percent, to 18,085.45, while the S&P 500 lost 53.49 points, or 2.45 percent, to 2,127.81. 
The Nasdaq Composite dropped 133.58 points, or 2.54 percent, to 5,125.91. 

Source : QNA