Elon Musk has taken the first step towards a $1.75tn stock market listing of SpaceX in what would be the biggest public debut in history.

The rocket business filed confidential paperwork this week with the US Securities and Exchange Commission to float in New York, Bloomberg reported. It paves the way for a stock market debut potentially as soon as June.

SpaceX is seeking to raise as much as $75bn, about three times the size of the next-biggest stock market float in history – that of Saudi Aramco in 2019.

The company’s expected valuation of $1.75tn would also narrowly pip Aramco. The state-owned oil giant was valued at $1.7tn when it listed some of its shares in 2019.

Mr Musk is preparing for an initial public offering despite ongoing market instability triggered by the war in Iran.

The June float would allow Mr Musk to get ahead of his bitter rival, Sam Altman. The two billionaires have been locked in a series of legal battles stemming from the founding of OpenAI, the company behind ChatGPT.

OpenAI, run by Mr Altman, is expected to join the stock market potentially as soon as this year.

News of the SpaceX filing came as OpenAI confirmed it had raised $122bn from investors as part of its latest funding round, increasing the total amount raised by about $12bn. The latest investment values OpenAI at $852bn.

Mr Musk has been targeting June for a SpaceX float, to time it to coincide with a rare planetary alignment of Jupiter and Venus. SpaceX was contacted for comment.

News that SpaceX, founded in 2002, has taken its first concrete step towards a float comes as Nasa prepares to launch a crucial test mission to the Moon as part of its Artemis programme intended to return humans to the lunar surface.

The space agency’s Artemis II mission is scheduled to blast off late on Wednesday night, taking astronauts on a flyby of the Moon. SpaceX is expected to take part in the upcoming lunar landings with its Starship mega-rocket, which is still in development.

SpaceX has been working with investment banks including Morgan Stanley, Bank of America, Goldman Sachs and JP Morgan on the planned float.

According to Reuters, the world’s richest man has also been preparing to allocate an unusually large portion of the company’s shares to retail investors, hoping to capitalise on his legions of fans.

Analysts have pointed out that the company’s ballooning valuation has been propped up by a “Musk premium”, which has similarly catapulted Tesla, his electric car business, to a valuation exceeding $1tn.

The SpaceX float will offer a potential major windfall for British investors, including Baillie Gifford. The Scottish investment business is a long-term backer of the rocket company.

SpaceX was most recently valued at $1.25tn in January after Mr Musk orchestrated a rapid merger with xAI, his artificial intelligence (AI) venture that controls the social network X and the chatbot Grok.

Mr Musk has argued that the high valuation is justified by SpaceX’s potential to supercharge the global AI race. He has announced plans to launch up to one million satellites that will form a network of data centres in space.

The satellites, launched on hundreds of rockets, will use abundant solar power to fuel superintelligent AI tools. Some analysts have raised questions about the plan’s viability.

Analysts have predicted that SpaceX could ultimately be combined with Tesla to bring together all the major businesses in Mr Musk’s empire.

Dan Ives, an analyst at Wedbush Securities, wrote in a recent note: “We continue to believe that SpaceX and Tesla will eventually merge into one company in 2027.”

Mr Musk is racing to take SpaceX public after more than two decades largely under his personal rule. The billionaire controls more than 42pc of the economic value in SpaceX and holds overall control of its voting stock.

Staying private has allowed Mr Musk to plough billions of dollars into high-stakes ventures, such as the construction of Starship.

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