The stock market had its worst drop in nearly a month as investors worried about more signs of weakness in China's economy. The slump was exacerbated by an ongoing sell-off in drugmakers' stocks.

The stock market had its worst drop in nearly a month as investors worried about more signs of weakness in China's economy. The slump was exacerbated by an ongoing sell-off in drugmakers' stocks.

On Monday:

The Dow Jones industrial average fell 312.78 points, or 1.9 percent, to 16,001.89.

The Standard & Poor's 500 index fell 49.57 points, or 2.6 percent, to 1,881.77.

The Nasdaq composite fell 142.53 points, or 3 percent, to 4,543.97.

For the year:

The Dow is down 1,821.18 points, or 10.2 percent.

The S&P 500 index is down 177.13 points, or 8.6 percent.

The Nasdaq is down 192.09 points, or 4.1 percent.