The Dow Jones industrial average fell 37.31 to 5,550.83, adding to Friday's 115-point plunge after bobbing slightly higher twice in the session.
Decliners led advancers by nearly a 7-to-3 margin Monday on the New York Stock Exchange, with 762 up, 1,735 down and 660 unchanged. NYSE volume totaled 366.31 million shares, vs. 181.45 million in Friday's holiday-abbreviated session.
Broad-market indexes also faltered after holding steady for most of the session amid some bargain-hunting. The NYSE's composite fell 2.91 to 350.33; the Standard & Poor's 500-stock index dropped 4.92 to 652.52; the Nasdaq index lost 9.52 to 1,148.83; and the American Stock Exchange index fell 5.42 to 568.91.
The technology-laden Nasdaq index, which lost 23 points on Friday, spent much of the session in positive territory before slipping with the rest of the market.
On Friday, stocks dropped sharply after a robust report on June employment and wage growth reignited fears about rising consumer spending and corporate payroll costs, both of which can spur inflation.
After the jobs report, the 30-year Treasury bond plunged nearly 3 points, or about $30 for each $1,000 invested. That pushed up its yield, which rises when prices fall, to 7.18 percent. On Monday, bonds were almost unchanged, with the long-bond yield holding at 7.18 percent.