The U.S. stock market opened with the Dow Jones down 0.13%, the S&P 500 index down 0.03%, and the Nasdaq up 0.1%. NIO Inc. (NIO.N) rose about 6%, with first-quarter revenue guidance increasing year-over-year by 103.4% to 109.2%. BioNTech (BNTX.O) plunged about 19%, as the company's 2026 revenue guidance fell short of expectations.