March 8 (Reuters) - The Nasdaq opened lower on Monday as the passage of a $1.9 trillion COVID-19 relief package by the U.S. Senate lifted bond yields, pressuring richly valued technology stocks and sparking inflation concerns. The Nasdaq Composite dropped 15.9 points, or 0.12%, to 12904.264 at the opening bell. The Dow Jones Industrial Average rose 15.9 points, or 0.05%, to 31512.15, while S&P 500 rose 2.4 points, or 0.06%, at the open to 3844.39. (Reporting by Shashank Nayar in Bengaluru; Editing by Sriraj Kalluvila)