Advanced Micro Devices Inc AMD.O rose 1.1% after Citigroup upgraded the chipmaker's stock to "neutral" from "sell". By Devik Jain July 15 (Reuters) - U.S. stock indexeswere set to open lower on Thursday following the latest batch of quarterly corporate earnings reports, while data showed the number of Americans filing new claims for unemployment benefits fell last week as expected. Wall Street's main indexes have swung in line with rising inflation since mid-June, with investors fretting over a sooner-than-expected hawkish shift by the Federal Reserve amid signs of a steady economic rebound.