Jeff Bezos Backed Both AI Giants and Built a $41B Lab of His Own

In April 2026, Amazon committed $13 billion to Anthropic, the safety-focused AI lab that has made AWS its exclusive cloud provider. Two weeks later, OpenAI walked away from its exclusive arrangement with Microsoft and expanded its own AWS commitment to $100 billion over eight years. Meanwhile, Jeff Bezos had already been building Prometheus, a physical AI startup he co-founded that closed a $12 billion round in June at a $41 billion valuation, making it one of the most richly valued AI companies ever backed without a single public product.

Prometheus: Building an Artificial General Engineer

Prometheus launched in late 2025 with an initial raise of $6.2 billion, closing at a $38 billion valuation, according to Bloomberg. The founding thesis is specific: build software capable of automating the design and manufacture of complex physical systems, from jet engine components to pharmaceutical compounds. Bajaj and Bezos call the target an "artificial general engineer," an AI system that substitutes for the broad engineering judgment currently distributed across thousands of specialists. The company operates out of San Francisco, London, and Zurich.

By June 2026, Prometheus closed a second round of $12 billion, lifting its valuation to $41 billion. Investors in the second round included JPMorgan Chase, Goldman Sachs, and BlackRock, a sign that institutional capital beyond the traditional tech sector is now funding physical AI directly. Speaking on CNBC on June 11, Bezos pushed back on the perception that the company was opaque. "We're not being secretive," he said. "We're being careful." Total capital raised across both rounds stands at roughly $18.2 billion. The company has not yet shipped a public product.

StartupHub.ai tracks 2,619 companies in the physical AI and robotics sector. Prometheus ranks among the top pure-play physical AI startups in that universe by our composite score, which reflects technical output, funding trajectory, and commercial traction.

The Model-Layer Capture: Anthropic and OpenAI Both on AWS

Amazon's path to AI infrastructure dominance runs through model partnerships. Before April 2026, Amazon had already invested $8 billion in Anthropic across two tranches. Then in April 2026, Amazon committed a further $5 billion, bringing its invested total to $13 billion, with an option to deploy up to $25 billion more tied to commercial milestones, according to Bloomberg. In exchange, Anthropic committed to spending more than $100 billion on AWS technologies over 10 years, per TechCrunch. Anthropic trains Claude on Amazon's custom Trainium silicon and serves inference through Bedrock, Amazon's managed AI API.

Then OpenAI restructured its relationship with Microsoft. In late April 2026, CNBC reported that Microsoft's license to OpenAI intellectual property would no longer be exclusive: OpenAI could now serve models on any cloud provider. OpenAI expanded its commitment to AWS and brought its models onto Amazon's platform. AWS's AI revenue run rate crossed $15 billion in Q1 2026, with Bedrock customer token usage up 170% quarter-over-quarter, per Amazon's Q1 2026 earnings.

Beyond those two labs, Bezos's family office backed five additional AI startups in June 2026 alone, according to CNBC, and added CuspAI, a startup using AI to discover new chipmaking materials in partnership with Nvidia, in July. Bezos is covering the model layer, the inference layer, and the materials science layer that sits underneath chip fabrication.

Where Microsoft Still Leads, and Where the Gap Has Narrowed

Azure is not losing in revenue terms. Microsoft's cloud segment grew 40% year-over-year in Q1 2026, compared with AWS's 28%. Mustafa Suleyman's Microsoft AI division has embedded Copilot across Office 365 and enterprise software at a scale Amazon has not matched. Microsoft also has a direct monetisation path through its existing enterprise seat count: selling AI features on top of software that tens of millions of workers already use is a structural advantage Bezos does not replicate at Amazon. Together, the three hyperscalers drove more than $320 billion in combined cloud revenue over the prior four quarters, per CNBC analysis from April 2026.

But the structural bet Nadella made, building Microsoft's AI differentiation around exclusive access to OpenAI, has been partially unwound. Amazon now hosts both Anthropic's Claude models and OpenAI's models through Bedrock. Enterprises using AWS can access the two most commercially prominent frontier model families from a single API, without routing traffic through Azure. Google Cloud grew the fastest of the three hyperscalers in Q1 2026 at 82%, though off a substantially smaller absolute base than AWS or Azure.

The competitive picture is now less about which cloud has the best model relationship and more about which can offer the broadest model ecosystem without forcing a single-vendor commitment. Amazon's Bedrock is built for that multi-model reality. Microsoft's Copilot stack is more tightly integrated with OpenAI's GPT architecture. Both are defensible strategies for different enterprise buyer profiles.

What It Means

Bezos has assembled a position that does not depend on any single AI outcome. If Anthropic remains the leading safety-focused frontier lab, Amazon has backed it with $13 billion. If OpenAI retains its commercial lead, Amazon is now a primary cloud partner. If physical AI, automating complex engineering and manufacturing, becomes the next computing platform, Bezos has a personal $41 billion bet on that thesis through Prometheus. Microsoft's Suleyman runs a formidable enterprise AI operation, and Azure's revenue growth rate remains faster than AWS. But the structural moat Nadella held through OpenAI exclusivity narrowed sharply in April 2026. Bezos's coverage of the AI stack has only widened.

Sources

• Bloomberg: Bezos's Project Prometheus AI Lab Hits $38 Billion Valuation After Funding Round
• Bloomberg: Jeff Bezos' AI Startup Valued at $41 Billion in Funding Round
• TechCrunch: Prometheus Raises $12B to Build an Artificial General Engineer for the Physical World
• CNBC: Amazon to Invest Up to Another $25 Billion in Anthropic
• CNBC: OpenAI Brings Its Models to Amazon's Cloud After Ending Exclusivity With Microsoft
• CNBC: AWS Q1 2026 Earnings, Cloud Unit Reports 28% Sales Growth
• CNBC: Jeff Bezos' Family Office Backed Five AI Startups in June
• CNBC: Bezos Opens Up About AI Startup Prometheus After $12 Billion Raise

Editorial standards: every claim is sourced. Tips: [email protected]