SpaceX Briefly Passed Microsoft to Become the World's 4th Most Valuable Company

On June 16, 2026, SpaceX’s market value briefly touched roughly $2.94 trillion — edging past Microsoft’s ~$2.93 trillion to make it, for a few hours, the fourth most valuable company in the world. For a company that had been publicly traded for all of four days, it’s one of the most astonishing runs in stock-market history. The key word, though, is briefly. Here’s what happened, why, and how seriously to take it.

What actually happened

In mid-morning trading on June 16, newly public SpaceX (ticker SPCX) leapfrogged Microsoft on the market-cap leaderboard, slotting in at No. 4 behind only Apple, Alphabet (Google) and Nvidia. Along the way it had already passed Amazon.

Then it slipped. The pass was an intraday moment, not a settled ranking — SpaceX closed the session below Microsoft, and by some trackers settled back toward the $2.5 trillion range and 5th or 6th place as the surge cooled. So the accurate framing isn’t “SpaceX is the world’s fourth-biggest company.” It’s “SpaceX briefly became the world’s fourth-biggest company, then gave some of it back” — a snapshot of a wildly volatile stock, not a new equilibrium.

That nuance matters, because it’s the difference between a durable milestone and a moment of peak euphoria. This was the latter.

How fast it happened

The speed is the real story. SpaceX only just completed the largest IPO in U.S. history:

June 11 — priced at $135 a share, an implied valuation near $1.77 trillion.
June 12 — debut day. Shares closed around $161, up roughly 19%.
June 16 — the stock pushed past $200 (and higher still in extended trading), carrying the market cap to its ~$2.94 trillion peak.

That’s a gain of roughly 50% — and by some measures closer to 70% — from the IPO price in just a handful of sessions, adding on the order of $1.2 trillion in market value in barely a week. On its very first day it had already sailed past Broadcom, Meta and Tesla. Companies do not normally do this.

Who’s still ahead

It’s worth keeping the “No. 4” headline in perspective. The three companies above SpaceX at its peak weren’t close:

Apple sat near $4.4 trillion — far above SpaceX’s high-water mark.
Alphabet and Nvidia also remained comfortably ahead.

So SpaceX vaulting to fourth is remarkable, but it didn’t “catch” the top of the market — it caught Microsoft and Amazon, the lower rungs of the trillion-dollar club, and only for a moment.

Why the stock exploded

Several forces stacked up at once:

A genuine FOMO rally. After a record-breaking, heavily oversubscribed IPO, retail investors raced to buy a stock many had wanted exposure to for years. Demand far outran the available float, and options activity was frenzied — the classic recipe for a melt-up.
The Cursor deal landed the same week. SpaceX’s $60 billion all-stock acquisition of Cursor reinforced the narrative that this is no longer just a rocket company but an AI powerhouse — and, conveniently, a soaring stock made that all-stock deal cheap to pay for.
The AI story. With xAI and Grok folded in, SpaceX is now an AI bet as much as a space bet, and investors have been paying up for anything AI-adjacent.
A real cash engine underneath. Starlink gives the company actual, fast-growing revenue and operating profit — so the rally isn’t pure fantasy, even if the price ran ahead of the fundamentals.

The skeptics’ case

Not everyone is cheering, and the cautious voices are worth hearing precisely because the move was so fast.

Valuation vs. reality. SpaceX posted a GAAP net loss in 2025, driven by heavy Starship investment; Starlink is the profit center. A near-$3 trillion price tag bakes in years of flawless execution.
Analyst caution. CFRA’s Keith Snyder rates the stock a Sell, citing its “dependence on unproven outcomes including Starship commercialization, orbital AI compute, and xAI monetization,” and warning that “the market assigns too much value to future optionality and insufficient discount to execution risk.”
A likely correction. Even bullish observers note the obvious: a stock that rises 50–70% in a week on FOMO can give a lot of it back “once the hype cools off.” The intraday round-trip past Microsoft and back is arguably that process already starting.

What it means for Elon Musk

There’s a personal footnote: this rally repriced a huge chunk of Elon Musk’s net worth in real time. Until the IPO, his SpaceX stake was illiquid paper revalued only at funding rounds. Now it trades live — so on June 16, as SPCX spiked, his fortune did too, by tens of billions in a morning. It also gave him a surging public currency to fund acquisitions, which is exactly how the Cursor deal got paid for.

Why “briefly” is the whole point

Strip away the excitement and the takeaway is measured: a sensational, FOMO-fueled rally pushed a four-day-old public company to the doorstep of the world’s most valuable businesses — for a moment — before reality tugged it back. It’s a genuine milestone and a real sign of how the market views SpaceX’s combined space-and-AI ambitions. It is not yet a settled verdict. Watch where the stock sits in a few weeks, once the IPO frenzy fades, for the number that actually means something.

FAQ

Did SpaceX really pass Microsoft?

Briefly. On June 16, 2026, SpaceX’s market cap touched about $2.94 trillion in intraday trading, just above Microsoft’s ~$2.93 trillion, making it the world’s fourth most valuable company for a short time. It then fell back and closed below Microsoft.

What is SpaceX’s market cap?

It has been extremely volatile since the IPO, peaking near $2.94 trillion on June 16, 2026 before settling lower (around the $2.5 trillion area by some trackers). Because the stock is moving fast, any single figure dates quickly — check a live source for the current number.

Which companies are bigger than SpaceX?

At its peak, SpaceX trailed only Apple (near $4.4 trillion), Alphabet and Nvidia. It had overtaken Microsoft and Amazon, though Microsoft regained fourth place when SpaceX pulled back.

Why did SpaceX stock rise so fast?

A combination of a record, oversubscribed IPO, a retail-driven FOMO rally, its same-week $60 billion Cursor acquisition, and the broader AI narrative around xAI and Grok — all on top of Starlink’s real revenue.

Is SpaceX stock overvalued?

Some analysts think so, pointing to its 2025 GAAP loss, heavy Starship spending, and a valuation that prices in years of perfect execution. Others argue Starlink and the AI assets justify a premium. A pullback after such a fast run would not be surprising.

Stock prices and market caps move constantly and the figures here reflect a fast-moving few days in June 2026; nothing in this article is investment advice. Reviewed periodically.