Stocks mostly lower as biotechnology shares slammed

Last Updated Sep 25, 2015 4:23 PM EDT

NEW YORK - U.S. stocks lost the bulk of their steam on Friday, ensuring weekly losses, as biotechnology shares tumbled.

Scaling back from gain of more than 250 points, the Dow Jones industrial average (DJI) was finished up 113 points, or 0.7 percent, to 16,315.

Nike (NKE) paced blue-chip gains, up 9 percent after reporting results that easily beat analysts' estimates.

Erasing gains, the S&P 500 (SPX) shed nearly a point, or 0.1 percent, to 1,931, with the health sector leading losses among its 10 major industry groups.

The Nasdaq Composite (comp) turned lower, off 48 points, or 1 percent, to 4,687.

Major U.S. indexes had rallied throughout the session, with investors cheered by remarks late Thursday from Federal Reserve Chair Janet Yellen, who reiterated that the central back was on track to hike benchmark interest rates before the end of the year. She also said unexpected jolts to the economy could prompt monetary policy makers to change course.

"The market was encouraged by what Janet Yellen had to say -- it was a vote of confidence in the economy," Gus Faucher, a senior economist at PNC Financial Services Group, said.

Economic reports on Friday had the U.S. economy growing more than expected in the second quarter, up 3.9 percent at an annualized rate.

"The GDP release was positive for near-term economic growth," PNC's Faucher said. "It looks like consumers are spending, and businesses are investing. It's positive for growth going forward."

Separate data showed consumer sentiment declined less than forecast in September.