Anthropic Hits $965B Valuation, Overtakes OpenAI as Most Valuable AI Startup

Anthropic closed a $65 billion Series H funding round on May 28, 2026, pushing its post‑money valuation to $965 billion and leapfrogging OpenAI to become the most valuable private AI startup in the world, according to Reuters. The round was led by Altimeter Capital, Dragoneer, Greenoaks, and Sequoia Capital, with Coatue and ICONIQ as co‑leads.

The valuation jump is staggering. Anthropic was valued at just $380 billion in February 2026 after its Series G. Three months later, it has more than doubled. The company's run‑rate revenue crossed $47 billion earlier in May, driven by enterprise adoption of Claude across industries, Axios reported. OpenAI, by comparison, was last valued at $852 billion post‑money in March 2026.

The Series H round includes $15 billion of previously committed hyperscaler investments, including $5 billion from Amazon, Reuters noted. The remainder is new capital from a mix of traditional VCs and strategic infrastructure partners.

Notably, three major chip manufacturers joined the round: Micron Technology, Samsung, and SK Hynix. These are not typical AI investors — they are the companies that manufacture the memory and storage hardware that AI data centers run on. Their participation signals that the AI race is now as much about securing physical supply chains as it is about model performance.

The Series H round builds on an existing deep relationship with Amazon. In April 2026, Amazon committed up to $25 billion to Anthropic, and in return, Anthropic pledged to spend over $100 billion on AWS cloud infrastructure over the next 10 years, according to Reuters. This is one of the largest cloud commitments in history and ties Anthropic's infrastructure future to Amazon's cloud platform.

The scale of this deal explains why the valuation is so high. Investors are not just betting on Claude's chat capabilities — they are betting on the full stack: models, cloud infrastructure, and enterprise distribution. As Anthropic CFO Krishna Rao said in a statement, quoted by:² "This funding will help us serve the historic demand we are experiencing, stay at the research frontier and bring Claude to more of the places where work happens."

Both Anthropic and OpenAI are planning public listings potentially as early as this year, Reuters reported. The IPOs are driven by the need to fund staggering compute costs — training frontier models requires billions in infrastructure, and neither company can sustain that on private capital alone indefinitely.

The timing is notable. Gizmodo wrote that "Among AI‑first tech companies, Anthropic, the Claude one, is now technically worth more than OpenAI" after the funding news broke. This shift in investor sentiment — from OpenAI as the default AI leader to Anthropic as the new frontrunner — could reshape how both IPOs are priced and received.

Anthropic's rapid growth has come with operational challenges. Surging demand for Claude has forced the company to impose usage limits during peak hours and actively incentivize off‑peak usage by offering more compute at lower‑traffic times, Reuters reported. For builders who rely on Claude for daily development work, these capacity constraints are a real friction point.

The $65 billion raise is partly a response to this problem. Anthropic needs to buy more compute, build more data centers, and scale its infrastructure to meet demand. The Amazon deal and chip manufacturer partnerships are designed to solve the supply‑side bottleneck. But scaling infrastructure takes time — and in the meantime, developers may hit rate limits during work hours.

For developers building on the Claude API, a $965 billion Anthropic is good news. It means the company has the capital to continue rapid model iteration — Opus 4.8 shipped the same day as the funding announcement, and Reuters confirmed Mythos is coming "in the coming weeks."

The risk is that a company preparing for IPO may prioritize enterprise contracts and revenue growth over developer experience and API pricing. The Fast Mode price cut on Opus 4.8 is a positive signal, but the capacity constraints suggest Anthropic is stretched thin. For builders, the smart move is to have a backup model — GPT‑5.5 or Gemini Flash — for when Claude hits rate limits. The AI model market is now a genuine duopoly, and that means developers should be comfortable switching between both.