Today is a good day to be Elon Musk, presuming you don't mind being quite so intensely strange and divisive as Elon Musk is. SpaceX, his spaceflight, AI and telecommunications company, has made a $1.77tn debut on the US stock market after successfully conducting a record-breaking initial public offering (IPO). By the time the markets close, Musk is expected to be named the world's first trillionaire, extending his lead at the top of the list of the world's richest people by around $800bn.