Midday movers: American Express, AutoNation, Scholastic, and more

Investing.com -- U.S. stocks were rising on Friday, with sentiment boosted by a largely positive start to the quarterly earnings season, sending the Dow on its way to a 10th-straight day of gains.

Here are some of the biggest U.S. stock movers today:

• American Express (NYSE:AXP) stock fell 3.2% after the credit card giant lifted its total provisions for credit losses to $1.2 billion in the second quarter, compared with $410 million a year earlier. It still beat estimates for second quarter profit as its affluent customer base continued to spend.

• AutoNation (NYSE:AN) stock fell 9% after the auto retailer posted a sharp drop in used-vehicle sales as well as a rise in expenses, overshadowing better-than-expected quarterly revenue.

• CSX (NASDAQ:CSX) stock fell 3.5% after the U.S. railroad operator disappointed with its second quarter revenue, hit by a decline in intermodal volumes and lower fuel prices.

• PPG Industries (NYSE:PPG) stock was flat after the paints manufacturer recorded a drop in overall sales volumes in the second quarter, even as it raised its full-year profit forecast.

• Scholastic (NASDAQ:SCHL) stock rose 11% after the children's publishing and media company beat earnings expectations and announced it would increase its share repurchase amount by $100M.

• Intuitive Surgical (NASDAQ:ISRG) stock fell 3% on a continued decline in growth rates for bariatric surgery in the U.S., even as the medical equipment manufacturer reported positive second quarter results.

• Carvana (NYSE:CVNA) stock fell 2.9% after Piper Sandler downgraded its stance on the used-car retailer to ‘neutral’ from ‘overweight’, saying it has little room for upside.