The Standard & Poor's 500 added to its record as U.S. stock indexes drifted through a quiet, mixed day on Wall Street

The S&P 500 was mostly unchanged, a day after setting an all-time high. The Dow Jones Industrial Average was down 122 points, or 0.3%, as of 12:18 p.m. Eastern time, and the Nasdaq composite was also mostly unchanged.

Microsoft was the strongest force pushing the S&P 500 upward. It rose 1.3% after saying it had developed what it calls the world’s first “quantum processing unit,” which cou