Tech billionaire Elon Musk’s space and artificial intelligence company, SpaceX, saw its market value fall by more than $600 billion over three days, extending its losses for a third consecutive day on Tuesday.

SpaceX’s shares fell 16 per cent on Monday to close at $154.60, bringing the three-day decline to 23 per cent, following the company’s announcement of its first investment-grade bond sale to fund its artificial intelligence expansion.

While the company’s stock remains 15 per cent higher than its initial public offering price of $135, set earlier in June, the sell-off has reduced its market value by more than $600 billion in three trading sessions.

SpaceX’s market value now sits above $2.1 trillion, making it the sixth-largest company in the United States, less than two weeks after its public market debut following a record $75 billion IPO priced at $135 per share.

Mr Musk briefly crossed the $1 trillion net worth mark earlier this month after SpaceX’s market debut pushed his combined wealth above that level, according to Forbes. 

It said SpaceX’s sell-off has cut Mr Musk’s net worth by more than $300 billion, as he owns nearly a 40 per cent stake.

Ipek Ozkardeskaya, senior market analyst at Swissquote Bank, said the company’s drift into bond financing for AI has renewed concerns that tech companies may be overspending on AI, according to Sky News.

“Jumping on the bond train to fund excessive AI and infrastructure spending revives earlier concerns that big tech may be spending too much on AI infrastructure and increasingly financing that spending through debt,” Ms Ozkardeskaya said.

Similarly, Nigel Green, chief executive of investment adviser deVere Group, said, “The AI trade became one of the most crowded trades in global markets.

“When everybody owns the same stocks, the exit door becomes very small very quickly.”