Shares at the world's largest retailer fell after a lengthy New York Times article told of Walmart executives having ignored in-house concerns over bribes given to hasten development in Mexico.
Walmart shares fell 4.66 percent. The Dow Jones industrial average, where Walmart is listed, lost 102.09 points or 0.78 percent to 12,927.17.
The tech-dominated Nasdaq composite index shed 30 points or 1 percent to 2,970.45. The Standard and Poor's 500 index gave up 11.59 points or 0.84 percent to 1,366.94.
On the New York Stock Exchange, 823 stocks advanced and 2,226 declined on a volume of 3.4 billion shares traded.
The 10-year treasury note rose 1/32 to yield 1.936 percent.
The euro fell to $1.3156 from Friday's $1.3218. Against the yen, the dollar fell to 81.12 yen from Friday's 81.55 yen.
In Tokyo, the Nikkei 225 index dropped 0.2 percent, 19.19, to 9,542.17.
In London, the FTSE 100 index shed 1.85 percent, 106.58, to 5,665.57.