On Thursday Reuters reported that Apple has become the first $1 trillion publicly listed U.S. company. The tech company’s stock jumped 2.8 percent to as high as $207.05, bringing its gain to about 9 percent since Tuesday, when the company said it had bought back $20 billion of its own shares. Apple’s stock market value is now greater than the combined capitalization of Exxon Mobil and AT&T, and now accounts for 4 percent of the S&P 500.