SpaceX has confidentially filed for an initial public offering on the US stock market, according to reports from Bloomberg and the Wall Street Journal. The IPO is set to be one of the most closely watched and highly valued listings in market history.Elon Musk’s company, which has become a dominant power in both space travel and satellite communications, could potentially seek a valuation upwards of $1.75tn. The confidential filing will give regulators a period to review and discuss the company’s...