Stocks plummeted Thursday after the nation's major retailers said shoppers cut back their spending last month and the government said unemployment claims rose last week. The troubling readings on the economy arrived ahead of the highly anticipated August employment report. The Dow Jones industrial average fell more than 340 points — its worst daily performance since June 26.

• The Dow Jones industrial average sank 344.65, or 2.99 percent, to 11,188.23.

• The Standard & Poor's 500 index fell 38.15, or 2.99 percent, to 1,236.83.

• The Nasdaq composite index dropped 74.69, or 3.20 percent, to 2,259.04.