Ambitions for SpaceX include building a civilisation on Mars and putting data centres in space - Steve Nesius/Reuters Investment platforms, including AJ Bell, Hargreaves Lansdown and eToro, will give ordinary retail investors the chance to buy shares in Elon Musk’s rocket company as part of the so-called “book-building” process. This is where investment banks take orders before a stock market listing to gauge interest and set the price at which the stock will start trading.