Nvidia’s startling ascent in the stock market reached another milestone Tuesday as the chipmaker rose to become the most valuable company in the S&P 500. Investors now say the company is worth over $3.3 trillion. Nvidia has seen soaring demand for its semiconductors, which are used to power artificial intelligence applications. Revenue more than tripled in the latest quarter from the same period a year earlier. The company’s journey to be one of the most prominent players in AI has...