Weakness in the health care and technology sectors dragged the U.S. stock market lower.
Health care stocks, which have risen more than other industries over the past year, fell sharply on Monday.
Pfizer had the biggest loss in the Dow Jones industrial average, 2 percent. Biotech stocks continued a decline that began Friday after lawmakers questioned the pricing of a Hepatitis C drug.
The Standard & Poor’s 500 index fell nine points, or 0.5 percent, to close at 1,857.
The Dow lost 26 points, or 0.2 percent, to 16,276.
The technology-heavy Nasdaq composite fell 50 points, or 1.2 percent, to 4,226.
Facebook, which has more than doubled over the past year, fell 5 percent.
Bond prices rose. The yield on the 10-year Treasury note fell to 2.73 percent.