Elon Musk became the world's first trillionaire on Friday after shares of his space technology company, SpaceX, jumped 25% on the first day of trading. The surge helped lift the wealth of the company's founder and chief executive beyond the trillion-dollar threshold.Musk founded SpaceX in 2002 and continues to lead the company as chief executive. (AP/Bloomberg)The share price increase valued the company at $2.21 trillion. Musk, who is also Tesla's chief executive and one of its largest shareholders, now has an estimated net worth of $1.1 trillion, according to Forbes.From manufacturing electric vehicles to developing technology that links computers and...