SpaceX briefly passed Amazon to become the fifth-most valuable company in the world, and nearly eclipsed Microsoft, before the company’s shares pared back those gains before the market closed Tuesday.

The newly-public company’s stock had already climbed 20% on Monday — its first full day of trading. Tuesday’s news that SpaceX was acquiring AI coding company Cursor, along with the start of options trading on SpaceX’s shares, sent the share price even higher, spiking its valuation to $2.9 trillion before it ultimately settled back down.

This is all despite the fact that SpaceX posted a $4.9 billion loss on $18.7 billion in revenue last year, compared to Amazon, which turned a $78 billion profit in 2025 on $717 billion in sales in 2025. SpaceX has recently added new revenue streams in the form of compute leasing deals with Anthropic and Google, though, and will absorb the revenue from Cursor when that deal closes in the third quarter.

The Anthropic and Google deals are non-binding, but investors don’t seem to mind either way. Elon Musk’s space-and-AI company had added roughly $1 trillion to its valuation since going public on Friday.

That transaction netted SpaceX nearly $86 billion in fresh capital, largely on promises that it can create an AI business worth trillions of dollars — a wild claim for a company that recently tore its AI division down to the studs.

SpaceX first revealed a collaboration with Cursor in April, at a time when Musk said his AI company xAI — now a part of SpaceX — “was not built right [the] first time around” and that he was rebuilding it “from the foundations up.” SpaceX is making the acquisition with $60 billion in company shares.

SpaceX’s historic IPO saw it debut with a valuation of around $1.7 trillion, and the transaction raised nearly $86 billion for Musk’s company. SpaceX only made about 4% of its total shares available for trading, which experts predicted would make the stock more susceptible to wild swings.

That appeared to be the case Tuesday, as traders swapped more than 300 million SpaceX shares throughout the trading day — more than half of the 555 million available on the public market post-IPO, according to data from the Nasdaq stock exchange.

The volatility continued into after-hours trading, which saw SpaceX’s valuation briefly eclipse Amazon’s market cap for a second time before falling again.