U.S. markets opened higher Thursday led by better-than-expected earnings from McDonald's (MCD). The fast food chain reported its first same store sales increase in 2 years. The new CEO Steve Easterbrook says that the crispy chicken sandwich and all day breakfast helped boost sales in the quarter. Things weren't so great at Caterpillar (CAT), however. The multinational company said the continued weakness in the oil and mining industries is still weighing on Caterpillar's results. Eli Lilly (LLY) also saw a better-than-expected earnings report and raised its outlook for the rest of this year. It reported strong sales of certain drugs and its animal health division performed better than expected.