The tech-heavy index advanced 0.8% to its 21st record close of the year. The S&P 500 added 0.3%, which was just shy of its high reached last month. The tech-heavy index advanced 0.8% to its 21st record close of the year. The S&P 500 added 0.3%, which was just shy of its high reached last month.
​WSJ.com: Markets