[U.S. Stock Market Opens Lower] According to Golden Finance, on May 21, U.S. stocks opened with declines: the Dow Jones Industrial Average fell 0.27%, the S&P 500 Index dropped 0.39%, and the Nasdaq Composite Index slid 0.5%. Microsoft (MSFT.O) rose 1.1% amid reports that Anthropic is in talks to use its artificial intelligence chips. U.S. Rare Earths (USAR.O) gained 2.7% as the company was selected for a U.S. Department of Energy pilot rare earth processing project. IBM (IBM.N) climbed 3% after the company secured $1 billion in U.S. government funding to advance quantum computing development. NIO Inc. (NIO.N) surged 5% as its first-quarter revenue increased by 112.2% year-over-year.