On a Saturday morning in December 2022, Elon Musk summoned finance executives at Twitter, which he had bought six weeks earlier, to a conference call. Then he drilled into a spreadsheet that contained the social media company’s expenditures.

Elon Musk’s SpaceX reportedly plans to launch a tender offer next month that would sell existing shares at a price of $135 each, valuing the company at more than $250 billion.