Several reports on the state of the US economy affected the market. A preliminary report from the analysis firm S&P Global Market showed that activity in the service sector decreased to the lowest level in 17 months. According to the survey, many companies blame the lack of optimism on President Donald Trump's tariff policy.
Another survey showed that many Americans expect inflation to rise, also a result of decided and announced new tariffs.
Among individual stocks, the plunge in insurance giant United Health Group was noted, down 7.2 percent, after the Justice Department launched an investigation into the company.
Calculated over the entire week, all three leading indices fell. The S&P 500 fell 1.7 percent, while the Dow Jones and Nasdaq fell 2.5 percent.
