[U.S. stock market opens with cryptocurrency concept stocks broadly declining, BMNR down 3.69%] BlockBeats news, on February 27, U.S. stock market opened with the Dow Jones down 0.75%, the S&P 500 index down 0.82%, and the Nasdaq down 1.2%. Amazon (AMZN.O) fell 0.44%, announcing a partnership with OpenAI and participating in OpenAI's new $110 billion investment round with a $50 billion contribution. In cryptocurrency concept stocks, MSTR fell 2.63%; COIN fell 3.12%; CRCL fell 3.21%; SBET fell 3.61%; BMNR fell 3.69%.