The Nasdaq fell as megacaps lost after having rallied for much of the year. Nvidia fell 3.5%, the biggest drop in nearly four months.

U.S. stocks have tended to fare well around the Federal Reserve's Jackson Hole gathering in August, according to a historical analysis from DataTrek Research, although the market has seen sizable moves in both directions in recent years.

Stocks start the week just shy of record highs, underpinned by a well-received corporate earnings season and hopes the Federal Reserve will soon start reducing official borrowing costs again. Investors are therefore keen that Friday’s keynote address by Fed Chair Jerome Powell at the Jackson Hole symposium will be suitably dovish.