Consumer companies were more or less flat amid concerns about elevated energy prices.
Research firm the Conference Board said its consumer confidence index fell to 93.1 in May from an upwardly revised 93.8 in April.
Concerns about rising prices caused consumers to delay major purchases, according to the survey.
Earnings from retailers such as Walmart last week confirmed fears about a bifurcation of consumer behavior, said one strategist.
"This was another example of the k-shape at work," said J.D. Joyce, president of Houston financial advisory Joyce Wealth Management.
