SpaceX has jumped more than 20 per cent in its Nasdaq debut as investors piled into the world's largest initial public offering and bet on Elon Musk's sprawling empire spanning rockets to AI.
The stock opened for trading at $US150, compared with the IPO price of $US135 per share.
It was last trading at $US164, lifting SpaceX's valuation to more than $US2 trillion ($A2.8 trillion) and making it the sixth largest US company by market value, behind only Nvidia, Apple, Google parent Alphabet, Microsoft and Amazon.
The deal was being closely scrutinised because of the stakes for the IPO market, which some bankers said could face difficulties if SpaceX shares closed below Thursday's pricing level.
The company's market debut is widely viewed as a dress rehearsal for a new generation of mega-listings, with market participants watching for signals on investor appetite ahead of forthcoming IPOs for AI heavyweights Anthropic and OpenAI.
The stock's performance will be a test for the so-called "Musk premium," which has been the force behind Tesla's $US1 trillion-plus valuation.
The landmark listing cemented Musk's status as the first trillionaire ever and propelled SpaceX into the ranks of the world's most valuable companies - even though the firm posted a loss of nearly $US5 billion last year and generated only a fraction of the revenue brought in by similarly valued tech giants.
"I gave SpaceX a 10 per cent chance of succeeding at all," Musk said in Texas, shortly before the opening bell.
SpaceX president Gwynne Shotwell and Chief Financial Officer Bret Johnsen rang the Nasdaq opening bell at 9.30am.
The record IPO is a culmination of Musk's long-held ambitions in space and technology, and has stood out for rewriting Wall Street's IPO playbook and drawing legions of retail investors into the market.
At $US75 billion, the deal's proceeds were more than double those of Saudi Aramco's record-setting 2019 IPO.
The valuation could rise further should underwriters exercise their right to sell additional shares, a decision typically made within 30 days after the offering.
Although SpaceX may have to wait for entry into the S&P 500, its expected fast-track inclusion in the Nasdaq 100 will soon make it a major holding for passive funds and ETFs that track the index, creating a fresh source of demand for its shares.
"We have to go back 100 years to get comparable entrepreneurs. He's a visionary unlike others, and he executes extremely well," said Joel Shulman, CEO of ERShares, which manages an ETF that has an exposure to SpaceX.
Some analysts expect SpaceX's debut to trigger a reshuffling of investor portfolios, creating selling pressure on other technology heavyweights as funds rotate into the stock.
with DPA
