Among stocks making big moves:
— Online deals company Groupon slumped $91 cents to $3.01 after it said after hours Thursday that it was hurt by the economic problems in Europe and growth failed to meet its expectations.
— J.C. Penney dropped $1.78 to $ 19.91 after the company reported a loss that was larger than investors were expecting. Shoppers have been abandoning the store after it got rid of blockbuster sales in favor of everyday low prices.
— Kayak Software surged $8.22 to $39.26 after the company said yesterday that it had agreed to be bought by Priceline.com Inc.