The Globe and Mail reports in its Thursday edition that a Tesla-SpaceX merger appears to be a matter of when, not if, to many on Wall Street -- the question is over how much Tesla shareholders should be paid. A Reuters dispatch to The Globe says Street predictions on the premium Tesla shareholders would get to swap into a stock of SpaceX that Elon Musk controls run from little or none to 35 per cent. With sister company Tesla worth $1.5-trillion, the premium could run into hundreds of billions of dollars (all figures U.S.). Tesla shares gained more than 3 per cent Wednesday, while SpaceX rose 7.8 per cent. SpaceX and Tesla are jointly developing the Terafab chip plant, and AI now makes up more than half of SpaceX's revenue, with another $35-billion to $40-billion spending likely in fourth quarter to finance further expansion. Analysts pointed to last week's Roadster unveiling, where a Tesla car built with SpaceX rocket thrusters flipped and leapt over vehicles, as a teaser for what a combined company could produce. However, much of the technology on which the lofty valuations of the companies are based, including data centres in orbit, self-driving taxis at scale and humanoid robots, has yet to reach commercial scale.