Stocks plummeted Tuesday on Wall Street after more data in China pointed to a sharp slowdown in the world's No. 2 economy.
At 2:10 p.m. ET, the Dow was down 428 points at 16,099. The New York Stock Exchange invoked a rarely used rule designed to smooth out volatility in the markets.
Data out overnight in China showed manufacturing there shrinking at the fastest pace in three years. China is an engine of the world economy and a major market for American goods.
American investors are also nervous about the prospect that the Federal Reserve will raise interest rates soon.
The Dow lost 6.6% of its value in August, making it the worst month for U.S. stocks in three years. That included extreme volatility last week: On Monday, the Dow plunged almost 1,100 points in six minutes at the start of trading.
The average has lost more than 10% of its value since its all-time high in May. It closed Monday at 16,528.
World markets sold off on Tuesday. Stocks closed down 4% in Japan and were down 2.3% in Frankfurt, 2.1% in London and 1.9% in Paris.