Stocks fall sharply in US as investors respond to weak earnings; Whole Foods, Exxon Mobil sink

U.S. stocks are sharply lower following weak corporate earnings. Exxon Mobil and Whole Foods slumped.

Argentina's stock market plunged 7 percent after the South American nation defaulted on its debt for the second time in 13 years.

European markets also fell as evidence mounted that the standoff between the West and Russia over Ukraine is hurting the region's economy.

The Dow Jones industrial average dropped 206 points, or 1.2 percent, to 16,675 as of noon Eastern time Thursday.

The Standard & Poor's 500 index fell 29 points, or 1.5 percent, to 1,941.

The Nasdaq composite fell 79 points, or 1.8 percent, to 4,383.

Small-company stocks fell more than the rest of the market. The Russell 2000 dropped 25 points, or 2.2 percent, to 1,121.