
The US stock market has closed with its worst performance in 18 months, driven lower by another slump in Chinese shares and heavy selling by technical traders.
The Standard & Poor's 500 index dropped 43 points, or 2.1%, to close at 2,035. It was the index's biggest percentage decline since February 2014.
The Dow Jones industrial average slid 358 points, also 2.1%, to 16,990. The Nasdaq fell 141 points, or 2.8%, to 4,877.
Worries over China were again the catalyst for the losses. The Shanghai Composite dropped 3.4% on Thursday on heavy selling of energy and property companies.
Strategists and traders say the US rout is also likely to be tied to programmed selling after the S&P 500 breached one of the most closely watched indicators, its 200-day moving average.