SpaceX Briefly Passed Amazon and Microsoft in Market Cap After Its IPO. Could It Get There Again?

In the early days following its IPO, Space Exploration Technologies (NASDAQ: SPCX) briefly topped $2.9 trillion in intraday trading, eclipsing both Amazon (NASDAQ: AMZN) and Microsoft's (NASDAQ: MSFT) 2026 low at the time.

However, the trajectories of those stocks have diverged significantly since then. As Amazon traded sideways and Microsoft surged, the space stock experienced a significant pullback as the IPO hype faded. With SpaceX now trading at about $147 -- below its opening-day first trading price of $150 -- its market cap is about $1.95 trillion.

In that light, investors might wonder if it's possible for SpaceX's market cap to once again surpass those of Amazon and Microsoft. Although anything is possible, investors should not expect it to reach such a milestone anytime soon unless it makes some unprecedented moves. Here's why.

Image source: The Motley Fool.

SpaceX's challenges

I found it sobering to see a newcomer to the public markets like SpaceX surpass those two tech giants, even briefly. Both Amazon and Microsoft started small and worked their way to tech sector leadership over the course of many years. It was remarkable to see a stock eclipse their market caps after trading for only a few days.

Nonetheless, that move now appears to have been an aberration, and few metrics show the size difference better than quarterly revenue.

In the second quarter of 2026 (or fiscal 2026 Q4 for Microsoft, which also ended June 30), SpaceX's revenue was just $7.8 billion. That was up 92% from the year-ago level, far surpassing the revenue growth rates of Amazon and Microsoft, at 20% and 18%, respectively.

However, Amazon's quarterly revenue was $201 billion. Even if one assumes that AWS's $42 billion in revenue was the company's only high-margin revenue, it is still far ahead of SpaceX. The same goes for Microsoft, which reported $90 billion in revenue in its fiscal Q4. This means that if revenue growth rates remain the same for all three companies (a highly unlikely prospect), it would take SpaceX approximately five years to catch up to Microsoft's revenue and about two additional years to match Amazon's.

Moreover, SpaceX is the only one of the three not currently earning a profit. Analysts have begun to project a turn toward profitability for the company in the coming quarters, so that could change soon. Still, that means SpaceX does not yet have a P/E ratio. But its price-to-sales (P/S) ratio of 95 far exceeds Amazon's sales multiple of 3.5 and Microsoft's P/S ratio of 12.

SpaceX's easiest path to the larger market cap

SpaceX has likely been granted such a high P/S ratio in part because of the track record of its CEO, Elon Musk. Also, even if it cannot sustain that valuation on its own, the most obvious potential catalyst for a SpaceX stock double would be a merger with Musk's other tech giant, Tesla.

Tesla's market cap is nearly $1.45 trillion, and it got there with a comparatively modest P/S ratio of 13. If Musk combines these companies, that would presumably take the market cap to about $3.4 trillion.

That is well above Amazon's $2.7 trillion market cap and only modestly lags Microsoft's current value of $3.8 trillion. Still, as a combined entity, SpaceX could more sustainably exceed the size of its "Magnificent Seven" counterparts.

Will SpaceX's market cap surpass that of Amazon and Microsoft?

SpaceX could become a larger company than Microsoft or Amazon, but it is unlikely to do so on its own for many years.

SpaceX's revenues are a small fraction of Amazon's and Microsoft's; it only eclipsed them because investors granted it a considerably higher P/S ratio. At current growth rates, it would take years for its top line to match that of Amazon or Microsoft.

However, a quick way to catch up would be to merge SpaceX with Tesla. With that move, it would surpass Amazon in size and come within striking distance of Microsoft. Conversely, if SpaceX and Tesla remain separate, I would expect SpaceX to stay smaller than its big tech counterparts for a long time to come.

Will Healy has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Amazon, Microsoft, and Tesla. The Motley Fool has a disclosure policy.