Stocks fell sharply, joining a global selloff of risky assets that deepened when the Federal Reserve said it would cut back further on its stimulus measures.

The Dow Jones Industrial Average slid 189.77 points, or 1.2%, to 15738.79. The S&P 500 gave up 18.30 points, or 1%, to 1774.20, and the Nasdaq Composite Index fell 46.53 points, or 1.1%, to 4051.43.

The...