xAI burned $6.4B last year. SpaceX’s IPO filing shows why the spending is far from over

The more consequential detail buried in this story is not the $6.4B loss itself but the structural arrangement it implies: xAI is simultaneously burning capital as a model developer while SpaceX's compute division is generating revenue by selling that same infrastructure to competitors. The entity losing money and the entity profiting from AI spending may share an owner, but they sit on opposite sides of the same transaction.

That tension becomes concrete when you read the Simon Willison coverage from the same day quoting the SpaceX S-1 directly. The filing reveals that Anthropic has committed $45 billion through 2029 for access to COLOSSUS and COLOSSUS II, the same systems xAI trains Grok on. So SpaceX is effectively monetizing the infrastructure that xAI depends on by leasing capacity to a direct Grok competitor. The $6.4B burn figure looks different once you account for the fact that some portion of that spending flows back to a Musk-controlled entity on the infrastructure side.

Watch whether the SpaceX IPO prospectus forces a cleaner accounting of intercompany compute transfers between xAI and SpaceX's infrastructure division. If those figures appear as a line item, they will clarify whether xAI's losses are genuine cash outflows or partially circular capital movements within the broader Musk portfolio.