Trading was cautious on the stock exchange in New York ahead of Friday's upcoming summit in Alaska between Presidents Donald Trump and Vladimir Putin.
The Dow Jones industrial index rose 0.1 percent, while the broad S&P 500 index and the technology-heavy Nasdaq's composite index fell 0.3 and 0.4 percent, respectively.
But the leading indexes have reached new record levels during the past week, largely thanks to increased hope among investors that the central bank Federal Reserve will lower the interest rate at its next meeting in September.
Among individual companies, the insurance giant United Health was noticed. The share soared 11.8 percent since it became known that financial icon Warren Buffett's investment company Berkshire Hathaway had bought shares in the company worth $1.6 billion, equivalent to 15 billion kronor. The United Health share had lost half of its value at the end of last month, counted from the turn of the year.
During the past week, the S&P 500 rose 0.9 percent, Nasdaq 0.8 percent, and Dow Jones 1.7 percent.
