UK investors were last night given a countdown to participate in the world’s biggest-ever stock market flotation – the $1.75trilllion (£1.3trillion) initial public offering of Elon Musk’s rocket company SpaceX.

Investors have until 7pm next Wednesday to apply for shares in the historic sale.

Thousands have already registered an interest with the platforms handling the IPO: Hargreaves Lansdown, AJ Bell, Barclays Private Bank, CMC Markets, Etoro, Freetrade, IG, Interactive Brokers, Interactive Investor and Revolut.

The highly-anticipated offer will give a rare chance to ordinary investors in Britain to participate in a major Wall Street event, should they wish to take a risk on what some argue is an overvalued offer.

SpaceX, whose key businesses are aerospace, satellites and artificial intelligence (AI) will be selling 555.6m shares at $135 each, raising £56billion. 

As was also disclosed yesterday in filings to the US financial regulator, additional shares could be offered in response to demand, increasing the proceeds to £64billion.

In a highly unusual move, 30 per cent of the offer will be reserved for private investors.

About £1.5billion is said to have been set aside for British investors who wish to back the Musk thrill ride. 

There will be no charges or stamp duty on the purchase of the shares, as is customary with an IPO.

Simon Belsham, chief client officer of Hargreaves Lansdown, pledged that the platform would be engaging with the many new investors expected to be taking part in the float to ‘make informed decisions on whether SpaceX is the right investment for them, but also on how to build a well-diversified portfolio for the long term’.

The money that is raised through the fundraising is to be spent developing SpaceX’s AI infrastructure, which is crucial to the whole company’s success. 

SpaceX’s £1.3 trillion valuation hinges on revenues from its xAI division rising a hundredfold from £2.4billion in 2025 to £240billion by 2030, according to projections by Goldman Sachs, the leading adviser to the IPO, reported by the Financial Times yesterday.

That could be controversial, given xAI’s Grok AI system is said to be lagging behind OpenAI’s ChatGPT and Anthropic’s Claude in being adopted by consumers and corporations.

It came as SpaceX launched an investor roadshow ahead of the June 12 IPO, featuring a 17-minute ‘hype video’ starring Bret Johnsen, the company’s chief financial officer.

Johnsen discusses SpaceX’s ambitions, including launching data centres orbiting in space and powered by the sun to provide the computing power for AI. The video also gives plans for SpaceX’s Starlink subsidiary.

Starlink has a network of satellites providing internet connectivity to 10.3m subscribers across the globe, with many in remote locations and war zones, and is the only profitable part of the group.

Among those pitching SpaceX to wealthy clients will be Jamie Dimon, chief executive of JP Morgan, another of the 23 institutions acting as advisers. Together, they are poised to pick up £370million from the flotation.

It also emerged yesterday that clients of the US platform Fidelity will be penalised if they try to ‘flip’, or sell, the shares for a quick profit within 15 days of the start of dealings on June 12.

Fidelity warned that ‘flipping’ would result in their clients’ exclusion from future IPOs.

This is a threat that they may take seriously, given that two more bumper flotations are expected within months. Coming to market in the wake of SpaceX will be both Anthropic and OpenAI.