SpaceX and Anthropic are preparing for what may be the biggest public-market launches in U.S. history, with OpenAI rumoured to be close behind.

That will put the companies' chiefs in the sights of the buttoned-down world of Wall Street, even as they sell moonshots in the form of rockets and artificial intelligence software that occasionally makes up answers.

The lead-up to an IPO is a high-stakes series of conversations and presentations where potential investors press company executives for a glimpse inside their books to gauge whether they will grow and make money - while the CEOs and their lieutenants must present themselves as trustworthy.

As the trillion-dollar IPOs draw near, they would do well to avoid the pitfalls that have dogged other market debuts.

As we have seen in past IPO periods, even billionaires, it seems, can be seduced by Playboy magazine.