Tech bubbles grow, fuelled by hype, and often they burst. But despite their bad rep, do these bubbles play an important part in progress?

For a company that built its reputation on rocket launches, SpaceX proved surprisingly keen to downplay that aspect as it prepared for its initial public offering (IPO) on the Nasdaq stock exchange in June. Instead, the story the company told was designed to support a valuation well over $1tn.

A chart in the prospectus summed up the company’s view of its ‘actionable total addressable market’. The chart showed digital advertising to be worth almost twice as much as the ‘space-enabled solutions’ that made it famous.

Even its Starlink satcoms operations were deemed to be far smaller than the estimates for the AI infrastructure the company apparently aims to build. Seeming to abandon its home turf of rocket science for artificial brain surgery does not paint a picture of assured growth. But the company did at least absorb xAI, developer of the GenAI chatbot...