The Dow Jones Industrials gave up earlier gains and retreated 39.03 points to 39,095.73.
The much-broader index shed 2.82 points to 5,470.35.
The NASDAQ recovered 26.91 points, to 17,748.50.
The S&P 500 is coming off a losing session after hitting an intraday record of 5,505.53, but headed for a 0.6% weekly advance. The NASDAQ is tracking for a 0.1% weekly loss, while the Dow is the outperformer, touting a 1.6% week-to-date rise.
Nvidia shares were down 2%. On Thursday, the stock hit an all-time high before closing more than 3% lower. Nonetheless, the chipmaker is still up nearly 150% year to date, and briefly beat Microsoft as the most valuable public company on Tuesday.
Trading on Friday could also be more volatile than normal due to triple witching, the expiration of stock options, stock index options and stock index futures options.
Prices for the 10-year Treasury slipped a bit, raising yields to 4.27% from Thursday’s 4.26%. Treasury prices and yields move in opposite directions.
Oil prices were unchanged at $81.29 U.S. a barrel.
Gold prices lost $30.20 to $2,338.80