Rocket Lab (RKLB +10.53%) stock soared to close up 10.4% on Thursday, despite having to abort a planned rocket launch yesterday to "assess sensor data."
The most likely reason for the shares rising in the face of, at best, neutral news on the business: Rocket Lab archrival SpaceX, already the biggest space company on the planet, is planning to get even bigger.
Potentially, $1.5 trillion big.
Because SpaceX will IPO in 2026.
Image source: Getty Images.
SpaceX versus Rocket Lab
What does this have to do with Rocket Lab? The connection isn't obvious, but a lot of investors (especially on "X") are trying to make it anyway. Here's one illustrative post:
SpaceX valuation: $1.5T
-- Hartik (@Hartik__) December 9, 2025
SpaceX expected 2026 sales: $23B
SpaceX Forward Value/Sales = 65X
Rocket lab valuation: $28.5B
Rocket lab expected 2026 sales: $900M
Rocket lab Forward Value/Sales = 32X$RKLB 👀 pic.twitter.com/aWJSCrYmcz
So, the logic seems to be that if SpaceX IPOs at a valuation of 65 times its expected 2026 sales, but Rocket Lab stock has a price-to-sales ratio only half that -- 32x -- then, obviously, Rocket Lab stock is going to double in price.
NASDAQ: RKLB
Key Data Points
Is Rocket Lab stock a buy?
There are at least a couple problems with that logic, though. First and most obviously, if it turns out that SpaceX stock is overvalued (and I would argue a $1.5 trillion valuation does overvalue SpaceX), then it doesn't logically follow that Rocket Lab stock will double at all. In fact, it might even fall.
The other issue I have with this thinking is that SpaceX and Rocket Lab are not equivalent companies. First and most obviously, because SpaceX is a profitable space business, and Rocket Lab isn't (at least not yet).
This isn't to say Rocket Lab isn't worth twice its present share price of $63 and change, of course. I just don't believe the case is quite as cut-and-dried that Rocket Lab is worth twice as much, as a lot of investors on social media seem to think it is.
