Check out the companies making headlines after the bell Thursday:
Mattel shares fell about 2 percent after the toymaker missed on the top and bottom lines. The results were "broadly in line with our expectations at this stage of our turnaround," the company said in its earnings release.
Yum Brands rose about 3 percent after the fast-food restaurant operator added activist investor Keith Meister to its board and reduced its outlook for earnings and China sales this year.
Advanced Micro Devices reported a wider-than-expected quarterly loss, but revenue topped estimates. The chipmaker also announced a joint venture with Nantong Fujitsu Microelectronics, a Chinese semiconductor manufacturer. The stock rose more than 2 percent after the bell.
Oilfield services provider Schlumberger saw its stock tick lower after it beat earnings estimates by a penny but missed on revenue. The company blamed pricing pressure for the disappointing results.
PTC Therapeutics slid as much as 17 percent after reporting mixed trial results for its experimental muscle disorder drug.
Wynn Resorts reported profit that was in line with estimates of 86 cents a share, but revenue came in at $996 million, falling short of Street projections of $1.03 billion. Shares tumbled 9 percent after hours.