Starship makes space access 1000x cheaper than before, with cost-to-orbit under $10 / kilogram. Also much larger payloads become possible. That's an insane economic unlock, because space contains unlimited amounts of resources and energy. Space-based manufacturing, building space hotels, mining asteroids etc. becomes viable. Larger satellites and probes for commercial or scientific use becomes possible.

All this might not make sense in a standard business sense. Real profits might be decades away, who knows. Anyway, people are willing to throw their money at it, because they think it's important.

If they succeed in the long term, it'll easily be the most valuable company on Earth.

No. Space is not lucrative or profitable. The SpaceX profit story rests entirely on Starlink. Starlink has a plausible moat servicing ships at sea and extreme remote areas. The big problem for Starlink is that they are trying to grow into a shrinking TAM, as terrestrial wireless expands with ever cheaper equipment ever farther into the countryside that Starlink is counting on for their TAM.

Elon's visions border on self parody. If I told you that humanoid robots were going to be digging tunnels for the Boring Company you'd have to stop and think if I was pulling your leg.

According to SpaceX's own documentation more than 80% of their value comes from xAI and their data centers. Starlink is where they are making the money, but they are pouring it into AI.

Because of the Musk reality distortion field. The claim is that all data centers will move into space, and that SpaceX will completely own that market.

One must also consider the proximity between musk and the trump administration, the market pricing this proximity is the market pricing power, access and aligning its interest with the blatant collusion between political power and business in the US.

That or the good ol’ « dump it on retail » scheme

People betting that the price will go up because they think other people are doing the same thing.

We know that xAI (with X) is struggling.

SpaceX is growing quite slowly. You could argue that Starship is likely to somewhat accelerate growth.

Starlink is doing well but also growing somewhat slow.

A more rational valuation would be 900b-1000b.

The rest is Musk and FOMO.

Monetary policy in the US is too loose and has been for years

The earth is finite, and space, for all intents and purposes, is not, and expansion into it would thus be required to sustain any super linear growth of the economy. Well, and rockets are cool. Perhaps people would much rather invest in something with the veneer of furthering space exploration (and the promise of infinite riches) than buy into some crypto blockchain startup. And, its not as if other current valuations are sane.

As long as you can offload your bag to the next sucker the value will be high.

Most shareholders don't really care about the company they have shares in.

Big picture: Nice-sounding economic theories claim that stock market valuations are rational, but those theories are mostly bullshit. As soon as the actual humans in the real-world stock market get excited, or scared, or otherwise emotional, they mostly stop caring about all that stupid boring gotta-do-math "rational" stuff.

Yes, eventually, the humans have to sober up, and stock market valuations return to approximately what the economic theories say they should be. But the dangers of betting on that "eventually" are very well known: https://quoteinvestigator.com/2011/08/09/remain-solvent/