Elon Musk's SpaceX has said it is even more valuable than anticipated as it approaches a public stock listing set for next week. In an filing with the US Securities and Exchange Commission detailing its plans for an initial public offering (IPO), SpaceX said its shares should go for $135 (£100) each, ratcheting up its own valuation of the firm to roughly $1.75tn. Setting an estimated price for its stock listing so far in advance is a rare move, and the amount represents a large increase in