A sharp selloff in health-care shares snapped the S&P 500’s five-day winning streak on Tuesday.

The Dow Jones Industrial Average gained 13.76 points, or 0.1%, to 16790.19. The S&P 500 lost 7.13, or 0.4%, to 1979.92, while the Nasdaq Composite fell 32.90, or 0.7%, to 4748.36.

Investors continued to hammer health-care stocks, particularly the...