Space Exploration Technologies Corp. (NASDAQ: SPCX) and IREN Ltd (NASDAQ: IREN) are both building businesses around NVIDIA Corp's (NASDAQ: NVDA) AI chips, but their economics could hardly look more different.

SpaceX is spending billions to build and operate AI infrastructure at enormous scale, while IREN is selling access to Nvidia-powered compute, offering investors a revealing test of whether the bigger opportunity lies in owning AI capacity or monetizing it.

• IREN stock is among today's weakest performers. What's weighing on IREN shares?

Two Ways to Build AI

SpaceX's reported plan to raise $40 billion to buy Nvidia chips puts the capital intensity of the AI race into sharp focus. The proposed financing would include $10 billion in bank loans and $30 billion of investment-grade debt.

The spending is already enormous. SpaceX reported $23.6 billion of AI capital expenditures in the first half of 2026, including $15.8 billion in the June quarter. AI revenue reached $2.56 billion in that quarter.

IREN is taking a different approach. It builds Nvidia-powered data centers and sells the resulting compute to customers. Its five-year Microsoft Corp (NASDAQ: MSFT) agreement is worth about $9.7 billion, while its AI Cloud business is scaling alongside Nvidia's GB300 systems.

That creates two very different bets on the same AI hardware: SpaceX is trying to own enormous amounts of compute, while IREN is trying to turn compute, power and data-center capacity into recurring revenue.

The Margin Gap

The early financials make the distinction even more striking.

IREN generated $128.8 million of AI Cloud revenue in fiscal 2026, against $16.9 million of cost of revenue excluding depreciation and amortization, implying an approximately 87% gross margin on that basis.

SpaceX's AI segment generated $3.2 billion of revenue in 2025 against $2.18 billion of cost of revenue, implying a roughly 32% gross margin.

The comparison needs a major caveat: SpaceX's AI segment includes X, Grok and AI infrastructure, so it is not a clean apples-to-apples comparison with IREN's AI Cloud business. Still, the numbers reveal the radically different economics of the two models.

Who Captures the AI Dollar?

For SpaceX, the bet is that owning and deploying vast amounts of compute will eventually generate enough revenue to justify the extraordinary upfront spending. The company itself says AI infrastructure requires substantial investment in computing hardware, data centers, energy and personnel.

IREN's model shifts more of that burden toward contracted customers and financing partners. That could make its infrastructure model more capital-efficient, but investors still need to see whether its unusually high early gross margin survives as the company scales.

Nvidia may sell the chips to both companies, but the more important question is where the AI industry's profits ultimately settle. SpaceX is betting on owning the compute; IREN is betting on selling access to it.

The margin gap is an early clue, but the real test will be whether those economics hold as both companies scale.