What Is Happening in the US Stock Market Today? Why Is US Stock Market Up Today? US Stock Market Today: Oil Stocks Steady as Hopes for US-Iran Agreement FluctuateMajor oil companies remained broadly steady after jumping about 4.5% on Monday. US Stock Market Today: Nvidia Shares RiseNvidia was one of the day’s important market stories. US Stock Market Today: What Investors Should Watch NextUS CPI: Wednesday’s consumer inflation report is the immediate macro trigger.